Golf equipment formed from castable formulation with unconventionally low hardness and increased shear resistance

ABSTRACT

Golf equipment including compositions including castable formulations that have low material hardness and increased shear resistance. The compositions may be used in any layer of a golf ball including cores, intermediate layers, and covers and result in high spin rates.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation application of U.S. patentapplication Ser. No. 13/709,936, filed Dec. 10, 2012, now U.S. Pat. No.8,907,040, which is a continuation application of U.S. patentapplication Ser. No. 13/204,131, filed Aug. 5, 2011, now U.S. Pat. No.8,329,850, which is a continuation application of U.S. patentapplication Ser. No. 12/184,738, filed Aug. 1, 2008, now U.S. Pat. No.7,994,269, which claims priority to provisional application No.60/935,786, filed on Aug. 30, 2007, the entire disclosures of which areincorporated by reference herein.

FIELD OF THE INVENTION

The invention relates to a castable composition that exhibits lowhardness, improved shear resistance, and desirable processingconditions. The castable composition may be useful in golf equipment,such as golf ball components and golf club components. In particular,the present invention is directed to castable polyurethane and polyureacompositions that have material hardnesses below about 30 Shore D, shearresistance that is equal or better to materials with hardnesses greaterthan 30 Shore D, and significant increases in spin rates compared tomaterials with hardnesses greater than 30 Shore D.

BACKGROUND OF THE INVENTION

Golf balls are formed from a variety of compositions, which provides agolf ball manufacturer the ability to alter feel and aerodynamiccharacteristics of a particular ball. For example, golf ball coversformed from balata allow a highly skilled golfer to achieve spin ratessufficient to more precisely control ball direction and distance,particularly on shorter shots. Balata covered golf balls are easilydamaged, however, which discourages the average golfer from using suchballs. To remedy this durability issue, manufacturers typically useionomer resin as a cover material. However, while ionomer resin coveredgolf balls possess virtually cut-proof covers, the spin and feel areinferior compared to balata covered balls.

Polyurethanes and polyureas have also been recognized as usefulmaterials for golf ball covers since the resulting golf balls aredurable like ionomer resin, but have the softer feel of a balata coveredgolf ball. U.S. Pat. No. 4,123,061 teaches a golf ball made from apolyurethane prepolymer formed of polyether with diisocyanate that iscured with either a polyol or an amine-type curing agent. In addition,U.S. Pat. No. 5,334,673 discloses the use of two categories ofpolyurethane available on the market, i.e., thermoset and thermoplasticpolyurethanes, for forming golf ball covers and, in particular,thermoset polyurethane covered golf balls made from a composition ofpolyurethane prepolymer and a slow-reacting amine curing agent, and/or adifunctional glycol. U.S. Pat. No. 5,484,870 discloses a polyureacomposition comprising the reaction product of an organic diisocyanateand an organic amine, each having at least two functional groups. Oncethese two ingredients are combined, the reaction rate is very fast and,thus, the ability to vary the physical properties of the composition islimited.

Despite the favorable characteristics of polyurethane and polyureamaterials for use in golf balls, ball components formed of thesematerials do not fully match ionomer resin golf ball components withrespect to resilience or the rebound (a function of the initial velocityof a golf ball after impact with a golf club). In addition, in order toachieve even adequate resilience and shear resistance, manufacturers aregenerally limited to material hardness ranges of 30 Shore D or greater.Moreover, manufacturing in the lower range of this hardness results in ahigh degree of non-concentric ball components due to viscosity issues.Furthermore, while the spin rates of polyurethane and polyurea coveredgolf balls are higher than ionomer covered balls, achieving an even highspin rate would provide more control.

Therefore, there remains a continuing need for golf equipment and, inparticular, golf balls having components formed from materials thatprovide the desired soft feel and, thus, higher spin, but still have atleast comparable resilience to that of ionomer resins without adverselyaffecting overall performance characteristics of the golf balls.

SUMMARY OF THE INVENTION

A golf ball including a core and a cover, wherein the cover is formedfrom a composition having a material hardness of about 8 Shore D toabout 14 Shore D including: a prepolymer having about 5 to about 7percent NCO groups, wherein the prepolymer is formed from the reactionproduct of an isocyanate-containing component and an isocyanate-reactivecomponent; and a curing agent including polyether diol, wherein thecover has a hardness of about 30 Shore D to about 60 Shore D, andwherein the golf ball has a coefficient of restitution of about 0.800 orgreater.

In one embodiment, the polyether diol has a molecular weight of about400 to about 2500. In another embodiment, the polyether diol has thestructure:

wherein n is the chain length from 2 to 30.

In this aspect of the invention, the golf ball may have at least one ofa driver spin rate of about 4000 rpm or greater, an 8-iron spin rate ofabout 10,000 rpm or greater, or a half-wedge spin rate of about 7,000 orgreater. In one embodiment, the driver spin rate is about 5000 rpm orgreater. In another embodiment, the driver spin rate is about 5200 rpmor greater.

The present invention is also directed to a golf ball including: a core;a layer disposed about the core to create an inner ball; and a coverhaving a hardness of about 40 Shore D to about 55 Shore D cast onto theinner ball, wherein the cover is formed from a composition having amaterial hardness of about 8 Shore D to about 12 Shore D including: aprepolymer formed from the reaction product of at least oneisocyanate-containing component and at least one hydroxy-terminatedisocyanate-reactive component, wherein the prepolymer has NCO content ofabout 5 percent to about 7 percent; and at least one curing agent.

The curing agent may include a polyether diol having a molecular weightof about 400 to about 2500. The composition may have a ratio ofprepolymer to curing agent of about 1:0.95. The golf ball may have aspin rate of about 5,000 rpm or greater when struck with a driver. Inone embodiment, the material hardness is about 10 Shore D to about 12Shore D. In another embodiment, the prepolymer has an NCO content ofabout 6 percent to about 6.5 percent. In yet another embodiment, thehydroxy-terminated isocyanate-reactive component includespolytetramethylene ether glycol.

The present invention also relates to a golf ball including: a core; anda cover having a hardness of about 40 Shore D to about 55 Shore D,wherein the cover is formed of a castable material including: aprepolymer formed from at least one isocyanate and at least one polyol,wherein the NCO content is about 5 percent to about 7 percent; and apolyether diol having a molecular weight of about 400 to about 800,wherein the castable material has a hardness of about 8 Shore D to about16 Shore D, wherein the golf ball has a spin rate of about 4,000 rpm orgreater when struck with a driver and a COR of about 0.800 or greater at125 ft/s.

In one embodiment, the COR of the golf ball is about 0.810 or greater.In another embodiment, the golf ball has a spin rate of 5,000 rpm orgreater when struck with a driver. In still another embodiment, theprepolymer includes a reaction product of diphenylmethane diisocyanateand polytetramethylene ether glycol. In yet another embodiment,polyether diol has the following structure:

wherein n is the chain length from 2 to 30.

BRIEF DESCRIPTION OF THE DRAWINGS

Further features and advantages of the invention can be ascertained fromthe following detailed description that is provided in connection withthe drawing(s) described below:

FIG. 1 is a cross-sectional view of a multi-component golf ball, whereinat least one layer is formed from a composition of the invention;

FIG. 2 is a cross-sectional view of a multi-component golf ballincluding a core, a thin inner cover layer, and a thin outer cover layerdisposed thereon, wherein at least one layer is formed from acomposition of the invention; and

FIG. 3 is a cross-sectional view of two-piece ball including a largecore and a cover, and an optional inner cover, wherein at least onecomponent is formed from a composition of the invention.

DETAILED DESCRIPTION OF THE INVENTION

The present invention contemplates improved polyurethane-based andpolyurea-based compositions for use in golf equipment, such as golfballs, golf clubs, or the like, that have material hardness values about30 Shore D or less, exceptional resiliency and shear resistance, andincreased spin rate. In particular, because of the softness of thematerial, the compositions of the invention, when used in golf ballcomponents, produce golf balls having high spin and at least comparablecoefficient of restitution values when compared to golf balls formedwith higher hardness materials.

The compositions of the invention are castable formulations including anisocyanate-containing component, an isocyanate-reactive component, and acuring agent. The resultant composition preferably has a materialhardness of about 30 Shore D or less, more preferably less than about 30Shore D, and even more preferably about 20 Shore D or less. In addition,the coefficient of restitution of golf balls formed with at least onecomponent including the composition of the invention is about 0.800 orgreater, preferably about 0.810 or greater. Moreover, the hardness ofthe component formed with the composition of the invention, e.g., a golfball cover, is about 30 to about Shore D, preferably about 30 Shore D toabout 50 Shore D, and more preferably about 35 Shore D to about 45 ShoreD.

The compositions of the invention may be used in a variety of golf ballconstructions, i.e., one-piece, two-piece, or multilayer balls, as wellas golf club components, e.g., club head and putter inserts. Thecompositions of the invention, when included into various golf ballcomponents, e.g., covers, produce golf balls with physical andaerodynamic properties better than or equal to golf balls incorporatingconventional polyurethane or polyurea compositions that traditionallyhave much higher material and ball hardness values.

COMPOSITIONS OF THE INVENTION

The compositions of the invention may include an isocyanate-containingcomponent and at least one isocyanate-reactive component. In oneembodiment, the compositions of the invention are polyurethane-based,i.e., compositions formed with an isocyanate-containing component, atleast one hydroxy-terminated isocyanate-reactive component, and at leastone curing agent. As used herein, the terms “formed from” and “formedof” denote open, e.g., “comprising,” claim language. As such, it isintended that a composition “formed from” or “formed of” a list ofrecited components be a composition comprising at least these recitedcomponents, and can further comprise other non-recited components duringformulation of the composition. The at least one curing agent may beamine-terminated or hydroxy-terminated.

In this aspect of the invention, the composition of the invention may beformed from a prepolymer and a curing agent. For example, theprepolymer, which is formed from the reaction product of anisocyanate-containing component and an isocyanate-reactive component, iscrosslinked with an curing agent. The curing agent reacts with anyexcess isocyanate and, as such, may be amine-terminated orhydroxy-terminated. In one embodiment, the prepolymer is cured with atleast one hydroxy-terminated component. In another embodiment, theprepolymer is cured with an amine-terminated component, which may bebased on a primary amine, a secondary amine, a tertiary amine, or acombination thereof. For example, if amine-terminated, the curing agentmay include secondary amine groups.

The compositions of the invention may contain urethane and/or urealinkages. As known to those of ordinary skill in the art, a compositionformed from an isocyanate-containing component and a hydroxy-terminatedcomponent consists essentially of urethane linkages whereas acomposition that is formed from an isocyanate-containing component andan amine-terminated isocyanate-reactive component consists essentiallyof urea linkages. In addition, compositions formed fromisocyanate-containing components and a mixture of amine-terminated andhydroxy-terminated components contain both urea and urethane linkages.For example, a prepolymer formed from an isocyanate-containing componentand a hydroxy-terminated isocyanate-reactive component may be cured withan amine-terminated curing agent to form a hybrid polyurethane/ureacomposition containing both urethane and urea linkages. Alternatively, aprepolymer formed from an isocyanate-containing component and anamine-terminated isocyanate-reactive component may be cured with ahydroxy-terminated component to form a hybrid polyurea/urethanecomposition.

In this regard, in one embodiment of the invention, the compositions ofthe invention include urethane linkages, i.e.,

where x is the chain length, i.e., about 1 or greater, and R and R₁ areany alkyl group having from about 1 to about 20 carbon atoms, preferablyabout 1 to about 12 carbon atoms, a phenyl group, a cyclic group, ormixture thereof. In one embodiment, at least one of R and R₁ arestraight chain or branched hydrocarbon chains having about 1 to about 20carbons. In another embodiment, both R and R₁ are straight chain orbranched hydrocarbon chains having about 1 to about 20 carbons. For thepurposes of this disclosure, the subscript letters such as m, n, x, y,and z used herein within the generic structures are understood by one ofordinary skill in the art as the degree of polymerization (i.e., thenumber of consecutively repeating units). In the case of molecularlyuniformed products, these numbers are commonly integers, if not zero. Inthe case of molecularly non-uniformed products, these numbers areaveraged numbers not limited to integers, if not zero, and areunderstood to be the average degree of polymerization.

In another embodiment, the compositions of the invention consistessentially of urea linkages, i.e.,

where x is the chain length, i.e., about 1 or greater, and R and R₁ areany alkyl group having from about 1 to about 20 carbon atoms, preferablyabout 1 to about 12 carbon atoms, a phenyl group, a cyclic group, ormixture thereof. In one embodiment, at least one of R and R₁ arestraight chain or branched hydrocarbon chains having about 1 to about 20carbons. In another embodiment, both R and R₁ are straight chain orbranched hydrocarbon chains having about 1 to about 20 carbons. Thisaspect of the invention may be achieved by forming a composition basedon an isocyanate-containing component and at least one amine-terminatedisocyanate-reactive component.

The particular components of the compositions of the invention will bediscussed in greater detail below.

Isocyanate-Containing Component

Any isocyanate available to one of ordinary skill in the art is suitablefor use as the isocyanate-containing component according to theinvention. Isocyanates for use with the present invention includealiphatic, cycloaliphatic, aromatic-aliphatic, aromatic, any derivativesthereof, and combinations of these compounds having two or moreisocyanate (NCO) groups per molecule. The isocyanates may be organicpolyisocyanate-terminated prepolymers, low free isocyanate prepolymer,and mixtures thereof. The isocyanate-containing component may alsoinclude any isocyanate-functional monomer, dimer, trimer, or polymericadduct thereof, prepolymer, quasi-prepolymer, or mixtures thereof.Isocyanate-functional compounds may include monoisocyanates orpolyisocyanates that include any isocyanate functionality of two ormore. In one embodiment, the isocyanate functionality is about two toabout three. For example, the isocyanate functionality may range fromabout 2.1 to about 3.1. In another embodiment, the isocyanatefunctionality is 3.1 or, in other words, the isocyanate istrifunctional.

Suitable isocyanate-containing components include diisocyanates havingthe generic structure: O═C═N—R—N═C═O, where R is preferably a cyclic,aromatic, or linear or branched hydrocarbon moiety containing from about1 to about 20 carbon atoms. The isocyanate may also contain one or morecyclic groups or one or more phenyl groups. When multiple cyclic oraromatic groups are present, linear and/or branched hydrocarbonscontaining from about 1 to about 10 carbon atoms can be present asspacers between the cyclic or aromatic groups. In some cases, the cyclicor aromatic group(s) may be substituted at the 2-, 3-, and/or4-positions, or at the ortho-, meta-, and/or para-positions,respectively. Substituted groups may include, but are not limited to,halogens, primary, secondary, or tertiary hydrocarbon groups, or amixture thereof.

Examples of isocyanates that can be used with the present inventioninclude, but are not limited to, substituted and isomeric mixturesincluding 2,2′-, 2,4′-, and 4,4′-diphenylmethane diisocyanate (MDI);3,3′-dimethyl-4,4′-biphenylene diisocyanate (TODI); toluene diisocyanate(TDI); polymeric MDI; carbodiimide-modified liquid 4,4′-diphenylmethanediisocyanate; para-phenylene diisocyanate (PPDI); meta-phenylenediisocyanate (MPDI); triphenyl methane-4,4′- and triphenylmethane-4,4″-triisocyanate; naphthylene-1,5-diisocyanate; 2,4′-, 4,4′-,and 2,2-biphenyl diisocyanate; polyphenylene polymethylenepolyisocyanate (PMDI) (also known as polymeric PMDI); mixtures of MDIand PMDI; mixtures of PMDI and TDI; ethylene diisocyanate;propylene-1,2-diisocyanate; tetramethylene-1,2-diisocyanate;tetramethylene-1,3-diisocyanate; tetramethylene-1,4-diisocyanate;1,6-hexamethylene diisocyanate (HDI); octamethylene diisocyanate;decamethylene diisocyanate; 2,2,4-trimethylhexamethylene diisocyanate;2,4,4-trimethylhexamethylene diisocyanate; dodecane-1,12-diisocyanate;dicyclohexylmethane diisocyanate; cyclobutane-1,3-diisocyanate;cyclohexane-1,2-diisocyanate; cyclohexane-1,3-diisocyanate;cyclohexane-1,4-diisocyanate; methylcyclohexylene diisocyanate (HTDI);2,4-methylcyclohexane diisocyanate; 2,6-methylcyclohexane diisocyanate;4,4′-dicyclohexyl diisocyanate; 2,4′-dicyclohexyl diisocyanate;1,3,5-cyclohexane triisocyanate; isocyanatomethylcyclohexane isocyanate;1-isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclohexane;isocyanatoethylcyclohexane isocyanate; bis(isocyanatomethyl)-cyclohexanediisocyanate; 4,4′-bis(isocyanatomethyl)dicyclohexane;2,4′-bis(isocyanatomethyl)dicyclohexane; isophorone diisocyanate (IPDI);triisocyanate of HDI; triisocyanate of 2,2,4-trimethyl-1,6-hexanediisocyanate (TMDI); 4,4′-dicyclohexylmethane diisocyanate (H₁₂MDI);2,4-hexahydrotoluene diisocyanate; 2,6-hexahydrotoluene diisocyanate;1,2-, 1,3-, and 1,4-phenylene diisocyanate; aromatic aliphaticisocyanate, such as 1,2-, 1,3-, and 1,4-xylene diisocyanate;meta-tetramethylxylene diisocyanate (m-TMXDI); para-tetramethylxylenediisocyanate (p-TMXDI); trimerized isocyanurate of any polyisocyanate,such as isocyanurate of toluene diisocyanate, trimer of diphenylmethanediisocyanate, trimer of tetramethylxylene diisocyanate, isocyanurate ofhexamethylene diisocyanate, and mixtures thereof; dimerized uretdione ofany polyisocyanate, such as uretdione of toluene diisocyanate, uretdioneof hexamethylene diisocyanate, and mixtures thereof; modifiedpolyisocyanate derived from the above isocyanates and polyisocyanates;and mixtures thereof.

While the list above includes unsaturated diisocyanates, i.e., aromaticcompounds such as substituted and isomeric mixtures including 2,2′-,2,4′-, and 4,4′-diphenylmethane diisocyanate (MDI),3,3′-dimethyl-4,4′-biphenyl diisocyanate (TODI), toluene diisocyanate(TDI), polymeric MDI, carbodimide-modified liquid 4,4′-diphenylmethanediisocyanate, para-phenylene diisocyanate (PPDI), meta-phenylenediisocyanate (MPDI), triphenylmethane-4,4′-, andtriphenylmethane-4,4″-triisocyanate, napthylene-1,5,-diisocyanate,2,4′-, 4,4′-, and 2,2′-biphenyl diisocyanate, polyphenylenepolymethylene polyisocyanate (PMDI) (also known as polymeric PMDI), andmixtures thereof, that may be used with the present invention, the useof unsaturated compounds is preferably coupled with the use of a lightstabilizer or pigment as discussed below.

In one embodiment, saturated or aliphatic isocyanates, i.e., thoseisocyanate-containing components lacking carbon-carbon double bonds, areused to form the composition of the invention. Suitable saturatedisocyanates include, but are not limited to, ethylene diisocyanate;propylene-1,2-diisocyanate; tetramethylene diisocyanate;tetramethylene-1,4-diisocyanate; 1,6-hexamethylene diisocyanate (HDI);octamethylene diisocyanate; decamethylene diisocyanate;2,2,4-trimethylhexamethylene diisocyanate; 2,4,4-trimethylhexamethylenediisocyanate; dodecane-1,12-diisocyanate; dicyclohexylmethanediisocyanate; cyclobutane-1,3-diisocyanate;cyclohexane-1,2-diisocyanate; cyclohexane-1,3-diisocyanate;cyclohexane-1,4-diisocyanate; methylcyclohexylene diisocyanate (HTDI);2,4-methylcyclohexane diisocyanate; 2,6-methylcyclohexane diisocyanate;4,4′-dicyclohexyl diisocyanate; 2,4′-dicyclohexyl diisocyanate;1,3,5-cyclohexane triisocyanate; isocyanatomethylcyclohexane isocyanate;1-isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclohexane;isocyanatoethylcyclohexane isocyanate; bis(isocyanatomethyl)-cyclohexanediisocyanate; 4,4′-bis(isocyanatomethyl)dicyclohexane;2,4′-bis(isocyanatomethyl)dicyclohexane; isophorone diisocyanate (IPDI);triisocyanate of HDI; triisocyanate of 2,2,4-trimethyl-1,6-hexanediisocyanate (TMDI); 4,4′-dicyclohexylmethane diisocyanate (H₁₂MDI);2,4-hexahydrotoluene diisocyanate; 2,6-hexahydrotoluene diisocyanate;and mixtures thereof.

In particular, the isocyanate-containing component of the invention maybe an aromatic polyisocyanate based on diphenylmethane diisocyanate(MDI) with an NCO content of about 32 percent or less. In oneembodiment, the NCO content of the isocyanate-containing component isabout 25 percent or less. In another embodiment, the NCO content of theisocyanate-containing component is about 18 percent or less. In yetanother embodiment, the NCO content of the isocyanate-containingcomponent is about 7 percent to about 32 percent. Thus, in oneembodiment, the isocyanate-containing component may have about 32percent or less NCO and includes the following general structure:

Commercially available examples of such components include, but are notlimited to the Desmodur® line of aromatic isocyanates, available fromBayer MaterialScience LLP of Pittsburgh, Pa., such as Desmodur® E 23 A,E 28, E 210, E 743, E 744, VL, XO 672, XP 2619, and XP 7144, which haveNCO contents ranging from 7.5 to 31.5.

As discussed briefly above, aromatic-aliphatic isocyanates may also beused in the compositions of the invention. As used herein,aromatic-aliphatic compounds should be understood as those containing anaromatic ring, wherein the isocyanate group is not directly bonded tothe ring. As such, without being bound to any particular theory, theremoteness of the NCO groups to the aromatic ring inhibits or slow downthe discoloration of the material that is typically associated witharomatic compounds. One example of an aromatic-aliphatic compound is1,3-bis-isocyanato-1-methylene ethylene benzene (TMXDI), which has thefollowing general structure:

Both meta-tetramethylxylene diisocyanate (m-TMXDI);para-tetramethylxylene diisocyanate (p-TMXDI) are contemplated for usewith the present invention as suitable aromatic-aliphatic isocyanates.Further non-limiting examples of aromatic-aliphatic isocyanates include1,2-, 1,3-, and 1,4-xylene diisocyanate; trimerized isocyanurate of anypolyisocyanate, such as isocyanurate of toluene diisocyanate, trimer ofdiphenylmethane diisocyanate, trimer of tetramethylxylene diisocyanate,isocyanurate of hexamethylene diisocyanate, and mixtures thereof;dimerized uretdione of any polyisocyanate, such as uretdione of toluenediisocyanate, uretdione of hexamethylene diisocyanate, and mixturesthereof; a modified polyisocyanate derived from the above isocyanatesand polyisocyanates; and mixtures thereof. The aromatic aliphaticisocyanates may be mixed with any of the unsaturated or saturatedisocyanates listed above for the purposes of this invention.

Isocyanate-Reactive Component

The isocyanate-reactive component of the invention may be any componentthat reacts with the isocyanate-containing component and reduces oreliminates the free isocyanate groups. For example, hydroxy-terminatedisocyanate-reactive components may be used as the isocyanate-reactivecomponent in accordance with the invention.

Suitable hydroxy-terminated components for use as theisocyanate-reactive component include, but are not limited to, polyetherpolyols, polycaprolactone polyols, polyester polyols, polycarbonatepolyols, hydrocarbon polyols, and mixtures thereof. Both saturated andunsaturated polyols are suitable for use with the present invention. Thehydroxy-terminated components may have one or more hydrophobic segmentsand/or one or more hydrophilic segments. The molecular weight of asuitable hydroxy-terminated component may be from about 100 to about20,000, such as about 200, about 230, about 500, about 600, about 1,000,about 1,500, about 2,000, about 2,500, about 3,000, about 3,500, about4,000, about 5,000, about 8,000, about 10,000, or any numbertherebetween.

Suitable polyether polyols for use in the present invention include, butare not limited to, polytetramethylene ether glycol (PTMEG); copolymerof polytetramethylene ether glycol and 2-methyl-1,4-butane diol (PTG-L);poly(oxyethylene)glycol; poly(oxypropylene)glycol; ethylene oxide capped(polyoxypropylene)glycol; poly(oxypropylene oxyethylene)glycol; andmixtures thereof.

In one embodiment, the isocyanate-reactive component is PTMEG and has amolecular weight of about 1000 to about 5000, preferably about 1500 toabout 3000, and more preferably about 2000.

Suitable polycaprolactone polyols include, but not limited to,diethylene glycol initiated polycaprolactone; propylene glycol initiatedpolycaprolactone; 1,4-butanediol initiated polycaprolactone; trimethylolpropane initiated polycaprolactone; neopentyl glycol initiatedpolycaprolactone; 1,6-hexanediol initiated polycaprolactone;polytetramethylene ether glycol (PTMEG) initiated polycaprolactone;ethylene glycol initiated polycaprolactone; dipropylene glycol initiatedpolycaprolactone; and mixtures thereof.

Suitable polyester polyols include, but not limited to, polyethyleneadipate glycol; polyethylene propylene adipate glycol; polybutyleneadipate glycol; polyethylene butylene adipate glycol; polyhexamethyleneadipate glycol; polyhexamethylene butylene adipate glycol;ortho-phthalate-1,6-hexanediol polyester polyol; polyethyleneterephthalate polyester polyols; and mixtures thereof.

Examples of polycarbonate polyols that may be used with the presentinvention include, but is not limited to, poly(phthalatecarbonate)glycol, poly(hexamethylene carbonate)glycol, polycarbonatepolyols containing bisphenol A, and mixtures thereof.

Hydrocarbon polyols include, but not limited to, hydroxy-terminatedliquid isoprene rubber (LIR), hydroxy-terminated polybutadiene polyol,hydroxy-terminated polyolefin polyols, hydroxy-terminated hydrocarbonpolyols, and mixtures thereof.

Other polyols that may be used as the isocyanate-reactive component ofthe invention include, but not limited to, glycerols; castor oil and itsderivatives; Polytail H; Polytail HA; Kraton polyols; acrylic polyols;acid functionalized polyols based on a carboxylic, sulfonic, orphosphoric acid group; dimer alcohols converted from the saturateddimerized fatty acid; and mixtures thereof.

By using polyols based on a hydrophobic backbone, the compositions ofthe invention may be more water resistant than those compositions havingpolyols without a hydrophobic backbone. Some non-limiting examples ofpolyols based on a hydrophobic backbone include hydrocarbon polyols,hydroxy-terminated polybutadiene polyols, polyethers, polycaprolactones,and polyesters.

In addition to the hydroxy-terminated isocyanate-reactive components,any amine-terminated compound available to one of ordinary skill in theart is suitable for use as the isocyanate-reactive component.Amine-terminated components suitable for use as the isocyanate-reactivecomponent may have two, three, four, or more amine end-groups capable offorming urea linkages (such as with isocyanate groups), amide linkages(such as with carboxyl group), imide linkages, and/or other linkageswith other organic moieties. As such, the amine-terminated componentsdiscussed in this section may also be used as a curing agent to cure aprepolymer. The amine-terminated component may be aromatic, araliphatic,aliphatic, alicyclic, heterocyclic, saturated or unsaturated, and eachmolecule has at least two isocyanate-reactive amine groups independentlybeing primary or secondary. The amine-terminated segments may be in theform of a primary amine (NH₂) or secondary amines (NHR). Depending onthe number of isocyanate-reactive amine groups being present,amine-terminated components may be referred to as diamines, triamines,tetramines, and other higher polyamines.

The molecular weight of a suitable amine-terminated compound for use inthe invention may range from about 100 to about 20,000, about 100 toabout 15,000, about 100 to about 10,000 or any molecular weighttherebetween. In one embodiment, the amine-terminated compound is about200 or greater, preferably about 300 or greater, and even morepreferably about 500 or greater. In another embodiment, theamine-terminated compound molecular weight is about 5000 or less,preferably about 3,000 or less, and more preferably about 2,500 or less.For example, in one embodiment, the molecular weight of theamine-terminated compound is about 300 to about 3000.

The amine-terminated compound may include amine-terminated hydrocarbons,amine-terminated polyethers, amine-terminated polyesters,amine-terminated polycarbonates, amine-terminated polycaprolactones, andmixtures thereof. Each of these types of suitable amine-terminatedcomponents will be discussed in greater detail below.

For example, the isocyanate-reactive component may be anamine-terminated hydrocarbon having the following generic structure:

where x is the chain length, i.e., 1 or greater, n is preferably about 1to about 12, and R is any alkyl group having from about 1 to about 20carbon atoms, preferably about 1 to about 12 carbon atoms, a phenylgroup, a cyclic group, or mixture thereof.

In addition, amine-terminated polyethers having following genericstructures are suitable for use as the isocyanate-reactive componentaccording to the invention:

where x is the chain length, i.e., 1 or greater, n is preferably about 1to about 12, and R is any alkyl group having from about 1 to about 20carbon atoms, preferably about 1 to about 12 carbon atoms, a phenylgroup, a cyclic group, or mixture thereof. One example of anamine-terminated polyether is a polyether amine. As used herein,“polyether amine” refers to a polyoxyalkyleneamine containing primaryamino groups attached to the terminus of a polyether backbone. Due tothe rapid reaction of isocyanate and amine, and the insolubility of manyurea products, however, the selection of diamines and polyether aminesis limited to those allowing the successful formation of the polyureaprepolymers. In one embodiment, the polyether backbone is based ontetramethylene, propylene, ethylene, trimethylolpropane, glycerin, andmixtures thereof.

In one embodiment, the polyether amine has the generic structure:

wherein the repeating unit x has a value ranging from about 1 to about70, R is any alkyl group having from about 1 to about 20 carbon atoms,preferably about 1 to about 12 carbon atoms, a phenyl group, a cyclicgroup, or mixture thereof, and R₃ is a hydrogen, methyl group, or amixture thereof. Even more preferably, the repeating unit may be fromabout 5 to about 50, and even more preferably is from about 12 to about35.

In another embodiment, the polyether amine has the generic structure:

wherein the repeating units x and z have combined values from about 3.6to about 8 and the repeating unit y has a value ranging from about 9 toabout 50, R is an alkyl group having about 1 to about 20 carbons, aphenyl group, a cyclic group, or mixtures thereof, R₁ is —(CH₂)_(a)—,wherein “a” may be a repeating unit ranging from about 1 to about 10, aphenylene group, a cyclic group, or mixtures thereof, and R₃ is ahydrogen, methyl group, or a mixture thereof.

In yet another embodiment, the polyether amine has the genericstructure:H₂N—(R₁)—O—(R₁)—O—(R₁)—NH₂;H₂N—(R₁)—O—(R₁)—O—(R₁)—NHR; orRHN—(R₁)—O—(R₁)—O—(R₁)—NHRwherein R is an alkyl group having about 1 to about 20 carbons, phenylgroups, cyclic groups, or mixtures thereof, and wherein R₁ is—(CH₂)_(a)—, wherein “a” may be a repeating unit ranging from about 1 toabout 10, a phenylene group, a cyclic group, or mixtures thereof.

Suitable polyether amines also include, but are not limited to,methyldiethanolamine; polyoxyalkylenediamines such as,polytetramethylene ether diamines, polyoxypropylenetriamine,polyoxyethylene diamines, and polyoxypropylene diamines; poly(ethyleneoxide capped oxypropylene) ether diamines; propylene oxide-basedtriamines; triethyleneglycoldiamines; trimethylolpropane-basedtriamines; glycerin-based triamines; and mixtures thereof. In oneembodiment, the polyether amine used to form the prepolymer is one ofJeffamine® D-2000 and D-4000 (manufactured by Huntsman Corporation ofAustin, Tex.), which are amine-terminated polypropylene glycols withmolecular weights of 2000 and 4000, respectively.

The molecular weight of the polyether amine for use in the invention mayrange from about 100 to about 5000. In one embodiment, the polyetheramine molecular weight is about 200 or greater, preferably about 230 orgreater. In another embodiment, the molecular weight of the polyetheramine is about 4000 or less. In yet another embodiment, the molecularweight of the polyether amine is about 600 or greater. In still anotherembodiment, the molecular weight of the polyether amine is about 3000 orless. In yet another embodiment, the molecular weight of the polyetheramine is between about 1000 and about 4000, preferably about 1000 toabout 4000, and more preferably is between about 1500 to about 2500.Because lower molecular weight polyether amines may be prone to formingsolid polyureas during prepolymer preparation, a higher molecular weightoligomer, such as Jeffamine® D-2000 and D-4000, may be used.

In addition, the amine-terminated compound may include amine-terminatedpolyesters having the generic structures:

where x is the chain length, i.e., 1 or greater, preferably about 1 toabout 20, R is any alkyl group having from about 1 to about 20 carbonatoms, preferably about 1 to about 12 carbon atoms, a phenyl group, acyclic group, or mixture thereof, and R₁ and R₂ are straight or branchedhydrocarbon chains, e.g., alkyl or aryl chains.

Copolymers of polycaprolactone and polyamines may also be used as theisocyanate-reactive component of the invention. Suitable copolymersinclude, but are not limited to, bis(2-aminoethyl)ether initiatedpolycaprolactone, 2-(2-aminoethylamino) ethanol, 2-2(aminoethylamino)ethanol, polyoxyethylene diamine initiated polycaprolactone, propylenediamine initiated polycaprolactone, polyoxypropylene diamine initiatedpolycaprolactone, 1,4-butanediamine initiated polycaprolactone,trimethylolpropane-based triamine initiated polycaprolactone, neopentyldiamine initiated polycaprolactone, hexanediamine initiatedpolycaprolactone, polytetramethylene ether diamine initiatedpolycaprolactone, and mixtures thereof. In addition, polycaprolactonepolyamines having the following structures may be useful as theisocyanate-reactive component for use with the present invention:

where x is the chain length, i.e., 1 or greater, preferably about 1 toabout 20, R is one of an alkyl group having from about 1 to about 20carbons, preferably about 1 to about 12 carbons, a phenyl group, or acyclic group, and R₁ is a straight or branched hydrocarbon chainincluding about 1 to about 20 carbons.

Other suitable amine-terminated polycaprolactones include:

where x is the chain length, i.e., 1 or greater, preferably about 1 toabout 20, R is one of an alkyl group having from about 1 to about 20carbons, preferably about 1 to about 12 carbons, a phenyl group, or acyclic group, and R₁ is a straight or branched hydrocarbon chainincluding about 1 to about 20 carbons.

In another embodiment, the amine-terminated compound may be anamine-terminated polycarbonate having one of the following genericstructures:

where x is the chain length, which preferably ranges from about 1 toabout 20, R is one of an alkyl group having from about 1 to about 20carbons, preferably about 1 to about 12 carbons, a phenyl group, or acyclic group, and R₁ is a straight chain hydrocarbon or predominantlybisphenol A units or derivatives thereof.

Amine-terminated polyamides may also be used as the isocyanate-reactivecomponent of the invention. Suitable amine-terminated polyamidesinclude, but are not limited to, those having following structures:

where x is the chain length, i.e., about 1 or greater, R is one of analkyl group having from about 1 to about 20 carbons, preferably about 1to about 12 carbons, a phenyl group, or a cyclic group, R₁ is an alkylgroup having about 1 to about 12 carbon atoms, a phenyl group, or acyclic group, and R₂ is an alkyl group having about 1 to about 12 carbonatoms (straight or branched), a phenyl group, or a cyclic group. Thus,any of the above isocyanate-reactive components, as well as any of thepolyamine telechelics taught in U.S. Patent Publication No.2007/0093317, may be used as the isocyanate-reactive componentsaccording to the present invention.

Additional amine-terminated compounds that may be used asisocyanate-reactive components include, but are not limited to,poly(acrylonitrile-co-butadiene); poly(1,4-butanediol)bis(4-aminobenzoate) in liquid or waxy solid form; linear and branchedpolyethylenimine; low and high molecular weight polyethylenimine havingan average molecular weight of about 500 to about 30,000; poly(propyleneglycol) bis(2-aminopropyl ether) having an average molecular weight ofabout 200 to about 5,000; polytetrahydrofuran bis(3-aminopropyl)terminated having an average molecular weight of about 200 to about2000; and mixtures thereof, all of which are available from Aldrich ofMilwaukee, Wis.

Suitable poly(acrylonitrile-co-butadiene) compounds for use with thepresent invention have one of the following structures:

wherein x and y are chain lengths, i.e., greater than about 1, R is anyalkyl group having from about 1 to about 20 carbon atoms, preferablyabout 1 to about 12 carbon atoms, a phenyl group, a cyclic group, ormixture thereof, R₁ is a hydrogen, methyl group, cyano group, phenylgroup, or a mixture thereof, and R₂ is a hydrogen, a methyl group,chloride, or a mixture thereof. In one embodiment, the y:x ratio isabout 82:18 to about 90:10. In other words, thepoly(acrylonitrile-co-butadiene) may have from about 10 percent to about18 percent acrylonitrile by weight.

In another embodiment, the composition of the invention includes apoly(1,4-butanediol) bis(4-aminobenzoate) having one of the followingstructures:

where x and n are chain lengths, i.e., 1 or greater, and n is preferablyabout 1 to about 12, R and R₁ are linear or branched hydrocarbon chains,an alkyl group having from about 1 to about 20 carbons, preferably about1 to about 12 carbons, a phenyl group, a cyclic group, or mixturesthereof, and R₂ is a hydrogen, a methyl group, or a mixture thereof. Inone embodiment, R₁ is phenyl, R₂ is hydrogen, and n is about 2.

In yet another embodiment, at least one linear or branchedpolyethyleneimine having one of the following structures is used as theisocyanate-reactive component:

wherein x and y are chain lengths, i.e., greater than about 1, R is anyalkyl group having from about 1 to about 20 carbon atoms, preferablyabout 1 to about 12 carbon atoms, a phenyl group, a cyclic group, ormixture thereof, and R₁ is a hydrogen, methyl group, or a mixturethereof. In one embodiment, R₁ is hydrogen. In another embodiment, thecomposition of the invention includes a mixture of linear and branchedpolyethyleneimines as the isocyanate-reactive component.

In still another embodiment, the composition of the present inventionincludes a polytetrahydrofuran bis(3-aminopropyl) terminated compoundhaving one of the following structures:

where m and n are chain lengths, i.e., 1 or greater, n is preferablyabout 1 to about 12 and m is preferably about 1 to about 6, R is any onealkyl group having from about 1 to about 20 carbons, preferably about 1to about 12 carbons, a phenyl group, a cyclic group, or mixturesthereof, and R₁ and R₂ are hydrogen, methyl groups, or mixtures thereof.In one embodiment, both R₁ and R₂ are hydrogen and both m and n areabout 2.

By using amine-terminated moieties based on a hydrophobic segment, thepolyurea compositions of the invention may be more water resistant thanthose polyurea compositions formed with an amine-terminated hydrophilicsegment. Thus, in one embodiment, the amine-terminated compound includeshydrophobic backbone, e.g., an unsaturated or saturatedhydrocarbon-based amine-terminated compound. One example of anamine-terminated hydrocarbon is an amine-terminated polybutadiene.

In addition, as briefly described above, aromatic diamines may be usedas the isocyanate-reactive component, preferably with an ultravioletstabilizer or whitening agent. U.S. Pat. No. 5,484,870 provides suitablearomatic diamines suitable for use with the present invention, theentire disclosure of which is incorporated by reference herein. Forexample, useful aromatic polyamines include polyamines that have one ormore monocyclic or aromatic polycyclic (fused, spiro, and/or bridged)aromatic rings, where at least two isocyanate-reactive amine groups aredirectly attached to the rings. Such aromatic polyamines may have about6-60 carbon atoms and, in one embodiment, about 6-22 carbon atoms.Non-limiting examples of single-ring aromatic diamines include o-, m-,or p-phenylenediamine, 1,2-, 1,3-, or 1,4-bis(sec-butylamino)benzene,toluene diamine, 3,5-diethyl-(2,4- or 2,6-)toluenediamine,3,5-dimethylthio-(2,4- or 2,6-)toluenediamine, and 3,5-diethylthio-(2,4-or 2,6-)toluenediamine. Suitable fused polycyclic aromatic diaminesinclude, but are not limited to, 1,4-, 1,6-, 1,8-, and2,7-diaminonaphthalene.

Non-limiting examples of dual-ring aromatic polyamines include4,4′-diaminodiphenyl ether, 4,4′-diaminodiphenylmethane (“MDA”),4,4′-diaminodiphenylpropane, 3,3′-dimethyl-4,4′-diaminodiphenylmethane,3,3′-diethyl-5,5′-dimethyl-4,4′-diaminodiphenylmethane,3,3′-dichloro-4,4′-diaminodiphenylmethane (“MOCA”),3,3′-diethyl-5,5′-dichloro-4,4′-diaminodiphenylmethane,3,3′,5,5′-tetraethyl-4,4′-diaminodiphenylmethane (“MDEA”),3,3′,5,5′-tetraisopropyl-4,4′-diaminodiphenylmethane,3,3′-dimethyl-5,5′-diisopropyl-4,4′-diaminodiphenylmethane,3,3′-diethyl-5,5′-diisopropyl-4,4′-diaminodiphenylmethane,3,3′-dimethyl-5,5′-di-t-butyl-4,4′-diaminodiphenylmethane,2,2′-dichloro-3,3′,5,5′-tetraethyl-4,4′-diaminodiphenylmethane(“MCDEA”), 3,3′-dichloro-4,4′-diaminodiphenylmethane,2,2′,3,3′-tetrachloro-4,4′-diaminodiphenylmethane (“MDCA”),4,4′-bis(sec-butylamino)-diphenylmethane,3,3′-dichloro-2,2′,6,6′-tetraethyl-4,4′-diaminodiphenylmethane, andN,N′-dialkylamino-diphenylmethane.

In addition, triamines that may be used in forming the prepolymer of theinvention include N,N,N′,N′-tetramethyl-ethylenediamine,1,4-diazobicyclo(2,2,2)-octane,N-methyl-N′-dimethylaminoethylpiperazine, N,N-dimethylbenzylamine,bis-(N,N-diethylaminoethyl)-adipate, N,N-diethylbenzylamine,pentamethyldiethylenetriamine, N,N-dimethylclyclohexylamine,N,N,N′,N′-tetramethyl-1,3-butanediamine,N,N-dimethyl-beta-phenylethylamine, 1,2-dimethylimidazole, and2-methylimidazole. Other nonlimiting examples of triamines for use asthe isocyanate-reactive component of the invention include diethylenetriamine, dipropylene triamine, N-(aminopropyl)ethylenediamine,N-(aminoethyl)butylenediamine, N-(aminopropyl)butylenediamine,N-(aminoethyl)hexamethylenediamine, N-(aminopropyl)hexamethylenediamine,4-aminomethyloctane-1,8-diamine, (propylene oxide)-based triamines(a.k.a. polyoxypropylene triamines), trimethylolpropane-based triamines,glycerin-based triamines, 3-(2-aminoethyl)aminopropylamine (i.e.,N-(2-aminoethyl)-1,3-propylenediamine, N₃-amine),N,N-bis(2-((aminocarbonyl)amino)ethyl)urea,N,N′,N″-tris(2-aminoethyl)methanetriamine,N1-(5-aminopentyl)-1,2,6-hexanetriamine, 1,1,2-ethanetriamine,N,N′,N″-tris(3-aminopropyl)methanetriamine,N1-(2-aminoethyl)-1,2,6-hexanetriamine,N₁-(10-aminodecyl)-1,2,6-hexanetriamine, 1,9,18-octadecanetriamine,4,10,16,22-tetraazapentacosane-1,13,25-triamine,N1-(3-((4-((3-aminopropyl)amino)butyl)amino)propyl)-1,2,6-hexanetriamine,di-9-octadecenyl-(Z,Z)-1,2,3-propanetriamine, 1,4,8-octanetriamine,1,5,9-nonanetriamine, 1,9,10-octadecanetriamine, 1,4,7-heptanetriamine,1,5,10-decanetriamine, 1,8,17-heptadecanetriamine, 1,2,4-butanetriamine,1,3,5-pentanetriamine,N1-(4-((3-aminopropyl)amino)butyl)-1,2,6-hexanetriamine,2,5-dimethyl-1,4,7-heptanetriamine,N1-6-aminohexyl-1,2,6-hexanetriamine,6-ethyl-3,9-dimethyl-3,6,9-undecanetriamine, 1,5,11-undecanetriamine,1,6,11-undecanetriamine, N,N-bis(aminomethyl)methanediamine,N,N-bis(2-aminoethyl)-1,3-propanediamine, methanetriamine,N1-(2-aminoethyl)-N-2-(3-aminopropyl)-1,2,5-pentanetriamine,N1-(2-aminoethyl)-1,2,6-hexanetriamine,2,6,11-trimethyl-2,6,11-dodecanetriamine, 1,1,3-propanetriamine,6-(aminomethyl)-1,4,9-nonanetriamine, 1,2,6-hexanetriamine,N2-(2-aminoethyl)-1,1,2-ethanetriamine, 1,3,6-hexanetriamine,N,N-bis(2-aminoethyl)-1,2-ethanediamine,3-(aminomethyl)-1,2,4-butanetriamine, 1,1,1-ethanetriamine,N1,N1-bis(2-aminoethyl)-1,2-propanediamine, 1,2,3-propanetriamine,2-methyl-1,2,3-propanetriamine, and mixtures thereof.

Non-limiting examples of tetramines include triethylene tetramine (i.e.,bis(aminoethyl)ethylenediamine), tetraethylene tetramine, tripropylenetetramine, N,N′-bis(3-aminopropyl)ethylenediamine (a.k.a. N₄-amine,N,N′-1,2-ethanediylbis-(1,3-propanediamine), 1,5,8,12-tetrazadodecane),bis(aminoethyl)propylenediamine, bis(aminoethyl)butylenediamine,bis(aminopropyl)butylenediamine, bis(aminoethyl)hexamethylenediamine,bis(aminopropyl)hexamethylenediamine. Illustrative examples of otherhigher polyamines include tetraethylene pentamine, pentaethylenehexamine, polymethylene-polyphenylamine, and mixtures thereof.

In one embodiment, the isocyanate-reactive component of the invention isa secondary diamine or secondary triamine where the amine end groups ofthe base diamine or triamine are reacted with a ketone, such as acetoneor other suitable solvent, and reduced to create hindered secondaryamine end groups represented by the following terminal structure:

Without being bound to any particular theory, one reactive hydrogen oneach end group provides for more selective reactivity and makes thesecondary diamine or secondary triamine intrinsically slower to reactthat primary diamines, possibly because an amine with a high level ofstearic hindrance, e.g., a tertiary butyl group on the nitrogen atom,has a slower reaction rate than an amine with no hindrance or a lowlevel of hindrance.

In this regard, the molecular weight of the secondary diamine ispreferably between about 100 and 5000, preferably about 200 to about2500, and more preferably about 300 to about 2100. In one embodiment,the molecular weight of the secondary diamine isocyanate-reactivecomponent is about 1800 to about 2100, preferably about 1900 to about2075. When the isocyanate-reactive component is a secondary triamine,the molecular weight may range from about 50 to about 2000, preferablyabout 100 to about 1000, and more preferably about 300 to about 700. Forexample, the molecular weight of a suitable secondary triamine for useas the isocyanate-reactive component may range from about 500 to about600.

The secondary diamines and secondary triamines preferably have a lowamount of primary amine, i.e., less than about 5 percent, preferablyless than about 3 percent, and more preferably less than 2 percent. Inaddition, this category of isocyanate-reactive components have arelatively low kinematic viscosity as compared with otheramine-terminated components. For example, the kinematic viscosity ofsuitable secondary diamines and secondary triamines for use with thepresent invention may range from about 5 cSt to about 500 cSt at 25° C.(77° F.). In one embodiment, the kinematic viscosity of theisocyanate-reactive component is about 180 cSt to about 250 cSt at 25°C. (77° F.). In another embodiment, the kinematic viscosity ranges fromabout 5 cSt to about 50 cSt at 25° C. (77° F.).

Commercially available examples of suitable secondary diamines includeJEFFAMINE® XTJ-584, XTJ-585, and XTJ-576, available from HuntsmanCorporation. JEFFAMINE® XTJ-586, also available from Huntsman, is acommercially available secondary triamine for use as theisocyanate-reactive component.

In this aspect of the invention, a suitable secondary diamine for use asthe isocyanate-reactive component may be based on an amine-terminatedpolypropylene glycol (PPG) with the following representative structure:

where x is the chain length preferably about 1 or greater, and morepreferably about 1 to about 70. In one embodiment, x is about 2 to about68. In another embodiment, x is from about 25 to about 40, preferablyabout 30 to about 38. In yet another embodiment, x ranges from about 2to about 10. In still another embodiment, x is from about 60 to about70, preferably about 65 to about 70. The molecular weight of theamine-terminated PPG may range from about 200 to about 4500. In oneembodiment, the molecular weight is from about 210 to about 450. Inanother embodiment, the molecular weight is from about 1800 to about4200. In yet another embodiment, the molecular weight is from about 1900to about 2500. In still another embodiment, the molecular weight is fromabout 3800 to about 4200. Commercially available examples of suitablebase diamines for use in forming the secondary diamines includeJEFFAMINE® D-230, D-400, D-2000, and D-4000, available from HuntsmanCorporation.

The secondary triamine may be based on a triamine prepared by thereaction of propylene oxide with a triol initiator, followed byamination of the terminal hydroxyl groups, which are shown in thefollowing representative structure:

where n may range from 0 to about 2, preferably from 0 to about 1; x, y,and z are chain lengths, preferably 1 or greater; and R may be hydrogenor an alkyl group. Moles propylene oxide are represented by x+y+z, whichmay range from about 4 to about 90. In one embodiment, x+y+z is about 5to about 6. In another embodiment, x+y+z is from about 40 to about 60,preferably about 45 to about 55, and more preferably 48 to about 52. Inyet another embodiment, x+y+z is from about 70 to about 95, preferablyabout 80 to about 90, and more preferably about 83 to about 88.Commercially available base triamines suitable for use in forming thesecondary triamine include JEFFAMINE® T-403, T-3000, and T-5000,available from Huntsman Corporation.

Any one or more of the hydrogen atoms in the amine-terminated component(other than those in the terminal groups) may be substituted withhalogens, cationic groups, anionic groups, silicon-based moieties, estermoieties, ether moieties, amide moieties, urethane moieties, ureamoieties, ethylenically unsaturated moieties, acetylenically unsaturatedmoieties, aromatic moieties, heterocyclic moieties, hydroxy groups,amine groups, cyano groups, nitro groups, and/or any other organicmoieties. For example, the amine-terminated component may behalogenated, such as having fluorinated backbones and/or N-alkylatedfluorinated side chains.

In one embodiment, at least two isocyanate-reactive components areemployed where one isocyanate-reactive component is amine-terminated anda second is hydroxy-terminated. Any of the previously discussedamine-terminated and hydroxy-terminated components are suitable for usein this regard. However, as discussed above, once a hydroxy-terminatedisocyanate-reactive component is used, the composition includes urethanelinkages and, thus, is no longer pure polyurea for the purposes of thepresent invention. Rather, this composition includes both urea andurethane linkages.

In another embodiment, the isocyanate-reactive component is anaminoalcohol component, i.e., a polymer having at least one amine endgroup and at least one hydroxy end group. This category ofisocyanate-reactive components includes polymers that are linear,branched, block, graft, monodisperse, polydisperse, regular, irregular,tactic, isotactic, syndiotactic, stereoregular, atactic, stereoblock,single-strand, double-strand, star, comb, dendritic, and/or ionomeric,and also includes homopolymers, random copolymers, pseudo-copolymers,statistical copolymers, alternating copolymers, periodic copolymer,bipolymers, terpolymers, quaterpolymers, as well as derivatives of anyand all hydroxy-terminated and amine-terminated components disclosedherein.

Aminoalcohol components can have any of the polymer or copolymerstructures of the herein-described hydroxy-terminated andamine-terminated components, such as polyhydrocarbons (such aspolydienes), polyethers, polyesters (such as polycaprolactones),polyamides (such as polycaprolactams), polycarbonates, polyacrylates(such as polyalkylacrylates), polysiloxanes, and copolymers thereof.Suitable aminoalcohol components, including generic structures andspecific examples, are disclosed in U.S. Pat. Nos. 7,259,222 and7,105,628, the entire disclosures of which are incorporated by expressreference herein. For example, the aminoalcohol may include apolypropylene glycol-based amine and a caprolactone monomer.

Aminoalcohols useful in the present disclosure include any and allmonomers, oligomers, and polymers having at least one freeisocyanate-reactive hydroxy group and at least one freeisocyanate-reactive amine group. The hydroxy and amine groups may beprimary or secondary, terminal or pendant groups on the oligomeric orpolymeric backbone, and in the case of secondary or tertiary aminegroups, may be embedded within the backbone. Aminoalcohols can be linearor branched, saturated or unsaturated, aliphatic, alicyclic, aromatic,or heterocyclic. The aminoalcohol may have the following generalstructure:

where R is hydrogen, hydrocarbyl or hydroxyhydrocarbyl group (such as—R₁—OH) having about 1-12 carbon atoms, such as about 1-8 or about 1-4carbon atoms; R₁ is a divalent hydrocarbyl moiety having about 2-30carbon atoms; each x is independently about 1-15; and y is about 1-3. Rand R₁ can independently be acyclic, alicyclic or aromatic. Theseaminoalcohols include alkanolamines, N-(hydroxyhydrocarbyl)amines,hydroxypoly(hydrocarbyloxy)amines, and hydroxypoly(hydroxyl-substitutedoxyalkylene)amines, conveniently prepared by reaction of one or moreepoxides with amines, and are also known as alkoxylated amines (when yis 1) or diamines (when y is 2).

R₁ may also be linear or branched alkylene having about 2-30 carbonatoms, such as about 4 or 6 carbon atoms or any number therebetween,like ethylene, propylene, 1,2-butylene, 1,2-octadecylene, and the like.R can be methyl, ethyl, propyl, butyl, pentyl, or hexyl group.Non-limiting examples of these alkanolamines include monoethanolamine,diethanolamine, diethylethanolamine, ethylethanolamine,monoisopropanolamine, diisopropanolamine, butyldiethanolamine, and thelike. Non-limiting examples of hydroxyhydrocarbylamines include2-hydroxyethylhexylamine, 2-hydroxyethyloctylamine,2-hydroxyethylpentadecylamine, 2-hydroxyethyloleylamine,2-hydroxyethylsoyamine, 2-hydroxyethoxyethylhexylamine, and mixturesthereof.

The aminoalcohol may also be hydroxy-containing polyamine, such asanalogs of hydroxy monoamines, like alkoxylated alkylenepolyamines(e.g., N,N-(diethanol)ethylene diamines). Such polyaminoalcohols may beprepared by reacting one or more cyclic ethers such as those disclosedherein with the diamines and higher polyamines disclosed herein, such asalkylene polyamines, or with the various aminoalcohols, such as thosedisclosed herein, including primary, secondary, and tertiaryalkanolamines, with a molar ratio of about 1:1 to about 2:1. Reactantratios and temperatures for carrying out such reactions are known tothose skilled in the art. Specific examples of hydroxy-containingpolyamines include N-(2-hydroxyethyl)ethylenediamine,N,N′-bis(2-hydroxyethyl)ethylenediamine, 1-(2-hydroxyethyl)piperazine,mono(hydroxypropyl)-substituted tetraethylenepentamine,N-(3-hydroxybutyl)-tetramethylene diamine, and the like. Higher homologsobtained by condensation of the above-illustrated hydroxy-containingpolyamines through amine and/or hydroxyl groups are likewise useful.Condensation through amine groups can result in a higher amineaccompanied by removal of ammonia while condensation through thehydroxyl groups can result in products containing ether linkagesaccompanied by removal of water.

Other examples of aminoalcohols includeN-(2-hydroxyethyl)cyclohexylamine, 3-hydroxycyclopentylamine,parahydroxyaniline, 2-propanol-1,1′-phenylaminobis,N-hydroxyethylpiperazine, 2-aminoethanol, 3-amino-1-propanol,1-amino-2-propanol, 2-(2-aminoethoxy)ethanol,2-[(2-aminoethyl)amino]ethanol, 2-methylaminoethanol,2-(ethylamino)ethanol, 2-butylaminoethanol, diethanolamine,3-[(hydroxyethyl)amino]-1-propanol, diisopropanolamine,bis(hydroxyethyl)-aminoethylamine, bis(hydroxypropyl)-aminoethylamine,bis(hydroxyethyl)-aminopropylamine, bis(hydroxypropyl)-aminopropylamine,hydroxy-functional amino acids as described herein, and mixturesthereof.

Curing Agent

The curing agent for use with the present invention include, but are notlimited to, hydroxy terminated curing agents, amine-terminated curingagents, and mixtures thereof. As known to those of ordinary skill in theart, the type of curing agent used determines whether the composition ispolyurea/urethane or polyurea/urethane. For example, a prepolymercontaining only urethane linkages cured with a hydroxy-terminated curingagent is pure polyurethane because any excess isocyanate groups willreact with the hydroxyl groups of the curing agent to create moreurethane linkages. In contrast, if an amine-terminated curing agent isused with a prepolymer containing only urea linkages, the excessisocyanate groups will react with the amine groups of theamine-terminated curing agent to create more urea linkages resulting ina pure polyurea composition.

In one embodiment, the curing agent is a hydroxy-terminated curingagent. Suitable hydroxy-terminated curing agents include, but are notlimited to, ethylene glycol; diethylene glycol; polyethylene glycol;propylene glycol; 2-methyl-1,3-propanediol; 2,-methyl-1,4-butanediol;dipropylene glycol; polypropylene glycol; 1,2-butanediol;1,3-butanediol; 1,4-butanediol; 2,3-butanediol;2,3-dimethyl-2,3-butanediol; trimethylolpropane; cyclohexyldimethylol;triisopropanolamine; N,N,N′N′-tetra-(2-hydroxypropyl)-ethylene diamine;diethylene glycol bis-(aminopropyl)ether; 1,5-pentanediol;1,6-hexanediol; 1,3-bis-(2-hydroxyethoxy)cyclohexane;1,4-cyclohexyldimethylol; 1,3-bis-[2-(2-hydroxyethoxy)ethoxy]cyclohexane;1,3-bis-{2-[2-(2-hydroxyethoxy)ethoxy]ethoxy}cyclohexane;polytetramethylene ether glycol, preferably having a molecular weightranging from about 250 to about 3900;resorcinol-di-(β-hydroxyethyl)ether and its derivatives;hydroquinone-di-(beta-hydroxyethyl)ether and its derivatives;1,3-bis-(2-hydroxyethoxy)benzene; 1,3-bis-[2-(2-hydroxyethoxy)ethoxy]benzene; N,N-bis((3-hydroxypropyl)aniline;2-propanol-1,1′-phenylaminobis; and mixtures thereof. Thehydroxy-terminated curing agent may have a molecular weight of at leastabout 50. In one embodiment, the molecular weight of thehydroxy-terminated curing agent is about 2000 or less.

Of the list above, the saturated hydroxy-terminated curing agents arepreferred when making a light stable composition. Those saturatedhydroxy-terminated curing agents include, but are not limited to,ethylene glycol; diethylene glycol; polyethylene glycol; propyleneglycol; 2-methyl-1,3-propanediol; 2,-methyl-1,4-butanediol; dipropyleneglycol; polypropylene glycol; 1,2-butanediol; 1,3-butanediol;1,4-butanediol; 2,3-butanediol; 2,3-dimethyl-2,3-butanediol;trimethylolpropane; cyclohexyldimethylol; triisopropanolamine;N,N,N′,N′-tetra-(2-hydroxypropyl)-ethylene diamine; diethylene glycolbis-(aminopropyl) ether; 1,5-pentanediol; 1,6-hexanediol;1,3-bis-(2-hydroxyethoxy)cyclohexane; 1,4-cyclohexyldimethylol;1,3-bis-[2-(2-hydroxyethoxy)ethoxy]cyclohexane;1,3-bis-{2-[2-(2-hydroxyethoxy)ethoxy]ethoxy}cyclohexane;polytetramethylene ether glycol having molecular weight ranging fromabout 250 to about 3900; and mixtures thereof.

In this aspect of the invention, the curing agent may be based onpolytetrahydrofuran diol (also known as polytetramethylene etherglycol). For example, a suitable curing agent for use with the presentinvention may have the following structure:

where n is the chain length from 2 to 30. In one embodiment, n is about7 to about 8, about 12-13, about 26-27, or any number therebetween. Themolecular weight of this type of curing agent may range from about 200to about 3000, about 400 to about 2550, about 650 to about 2000, and anymolecular weight therebetween. The hydroxyl number (mg KOH/g) preferablyranges from about 50 to about 200, about 105 to about 120, about 50 toabout 60, about 165 to about 180, and any number therebetween.Commercially available examples of such hydroxy-terminated curing agentsinclude Poly THF® 650, 1000, and 2000, manufactured by BASF Corporation.

In another embodiment, the curing agent is amine-terminated. Suitableamine-terminated curing agents include, but are not limited to, ethylenediamine; hexamethylene diamine; 1-methyl-2,6-cyclohexyl diamine; 2,2,4-and 2,4,4-trimethyl-1,6-hexanediamine;4,4′-bis-(sec-butylamino)-dicyclohexylmethane and derivatives thereof;1,4-bis-(sec-butylamino)-cyclohexane;1,2-bis-(sec-butylamino)-cyclohexane; 4,4′-dicyclohexylmethane diamine;1,4-cyclohexane-bis-(methylamine); 1,3-cyclohexane-bis-(methylamine);diethylene glycol bis-(aminopropyl)ether;2-methylpentamethylene-diamine; diaminocyclohexane; diethylene triamine;triethylene tetramine; tetraethylene pentamine; propylene diamine;1,3-diaminopropane; dimethylamino propylamine; diethylamino propylamine;imido-bis-(propylamine); monoethanolamine, diethanolamine;triethanolamine; monoisopropanolamine, diisopropanolamine;isophoronediamine; 4,4′-methylenebis-(2-chloroaniline);3,5-dimethylthio-2,4-toluenediamine;3,5-dimethylthio-2,6-toluenediamine; 3,5-diethylthio-2,4-toluenediamine;3,5-diethylthio-2,6-toluenediamine;4,4′-bis-(sec-butylamino)-diphenylmethane and derivatives thereof;1,4-bis-(sec-butylamino)-benzene; 1,2-bis-(sec-butylamino)-benzene;N,N′-dialkylamino-diphenylmethane;trimethyleneglycol-di-p-aminobenzoate;polytetramethyleneoxide-di-p-aminobenzoate;4,4′-methylenebis-(3-chloro-2,6-diethyleneaniline);4,4′-methylenebis-(2,6-diethylaniline); meta-phenylenediamine;paraphenylenediamine; N,N′-diisopropyl-isophoronediamine;polyoxypropylene diamine; propylene oxide-based triamine;3,3′-dimethyl-4,4′-diaminocyclohexylmethane; and mixtures thereof. Inone embodiment, the amine-terminated curing agent is4,4′-bis-(sec-butylamino)-dicyclohexylmethane. In one embodiment, theamine-terminated curing agent may have a molecular weight of about 64 orgreater. In another embodiment, the molecular weight of the amine-curingagent is about 2000 or less. In addition, any of the amine-terminatedmoieties listed above may be used as curing agents to react with thepolyurea prepolymers.

Of the list above, the saturated amine-terminated curing agents suitablefor use with the present invention include, but are not limited to,ethylene diamine; hexamethylene diamine; 1-methyl-2,6-cyclohexyldiamine; 2,2,4- and 2,4,4-trimethyl-1,6-hexanediamine;4,4′-bis-(sec-butylamino)-dicyclohexylmethane;1,4-bis-(sec-butylamino)-cyclohexane;1,2-bis-(sec-butylamino)-cyclohexane; derivatives of4,4′-bis-(sec-butylamino)-dicyclohexylmethane; 4,4′-dicyclohexylmethanediamine; 1,4-cyclohexane-bis-(methylamine);1,3-cyclohexane-bis-(methylamine); diethylene glycol bis-(aminopropyl)ether; 2-methylpentamethylene-diamine; diaminocyclohexane; diethylenetriamine; triethylene tetramine; tetraethylene pentamine; propylenediamine; 1,3-diaminopropane; dimethylamino propylamine; diethylaminopropylamine; imido-bis-(propylamine); monoethanolamine, diethanolamine;triethanolamine; monoisopropanolamine, diisopropanolamine;isophoronediamine; and mixtures thereof.

The amine-terminated curing agent may also be an amine-functionalaspartic ester. For example, the amine-terminated curing agent may be apolyaspartate prepared from 2-methyl-1,5-pentane diamine. A commerciallyavailable example of this type of curing agent is Desmophen® NH 1220from Huntsman. Those of ordinary skill in the art would also be aware ofmethods of forming such amine-terminated curing agents. For example,U.S. Pat. No. 6,790,925, the entire disclosure of which is incorporatedby reference herein, discusses in-situ methods of preparing polyasparticesters that are suitable for use as the curing agent according to thepresent invention.

As briefly discussed above with regard to the use of a secondary diamineor secondary triamine as an isocyanate-reactive component, many aminesmay be undesirable for reaction with the isocyanate because of the rapidreaction between the free NCO groups and the amine end groups. This sameissue exists when selecting a suitable curing agent. For example, ingeneral, unhindered primary diamines are fast reacting and, thus, theselection of a primary diamine as the curing agent may be problematicdepending on the processing conditions. As such, in one embodiment, ahindered secondary diamine may be used as the curing agent. For example,4,4′-bis-(sec-butylamino)-dicyclohexylmethane or3,3′-dimethyl-4,4′-bis(sec-butylamino)-dicyclohexylmethane, both ofwhich are commercially available from Dorf Ketal as Clearlink® 1000 andClearlink® 3000, respectively, are suitable for use in combination withan isocyanate to form the polyurea prepolymer. In addition,N,N′-diisopropyl-isophorone diamine, available from Huntsman Corporationunder the tradename Jefflink®, may be used as the secondary diaminecuring agent. Furthermore, secondary diamines based on methylenedianiline may be used as curing agents. For example, Unilink® 4200,available from Dorf Ketal, is suitable for use as a curing agent.

Thus, both types of curing agents, i.e., hydroxy-terminated andamine-terminated curatives, may include one or more saturated,unsaturated, aromatic, and cyclic groups. Additionally, thehydroxy-terminated and amine-terminated curatives may include one ormore halogen groups. To further improve the shear resistance of theresulting polyurea elastomers, a trifunctional curing agent can be usedto help improve cross-linking. For instance, triols such astrimethylolpropane or a tetraol such as N,N,N′,N′-tetrakis(2-hydroxylpropyl)ethylenediamine may be added to the formulations.

In one embodiment, the curing agent is a modified curative blend asdisclosed in co-pending U.S. Pat. No. 7,041,769, which is incorporatedby reference herein in its entirety.

Forming the Compositions of the Invention

There are two basic techniques used to process the compositions of theinvention: the one-shot technique and the prepolymer technique. Theone-shot technique reacts the isocyanate-containing compound, theisocyanate-reactive compound, and an optional curing agent in one step,whereas the prepolymer technique requires a first reaction between theisocyanate-reactive compound and the isocyanate-containing compound toproduce a prepolymer, and a subsequent reaction between the prepolymerand a curing agent. Either method may be employed to produce thecompositions of the invention, however, the prepolymer technique isgenerally preferred because it provides better control of chemicalreaction and, consequently, results in more uniform properties for theresultant composition.

Thus, in one embodiment, the compositions of the invention may be formedby reacting at least one isocyanate-containing component with at leastone isocyanate-reactive component to form a prepolymer and chainextending the prepolymer with a curing agent to cure the system. Inparticular, any of the isocyanate-containing components disused earliermay be reacted with any of the isocyanate-reactive components discussedabove to form a prepolymer. For example, in one embodiment, theprepolymer is formed from an isocyanate-containing component and ahydroxyl-terminated isocyanate-reactive component and consistsessentially of urethane linkages.

In another aspect of the invention, the isocyanate-containing componentfor use with the present invention may include an aromatic isocyanatethat is hybridized with an aliphatic isocyanate. For example, anaromatic isocyanate may be reacted with an isocyanate-reactivecomponent, such as an amine-terminated component, to form anintermediate prepolymer and then the prepolymer is heated at atemperature sufficient to allow further reaction between the functionalgroups of the prepolymer and an aliphatic isocyanate, which is added inexcess. The result is a prepolymer with aliphatic isocyanate groups atboth ends. In one embodiment, the temperature sufficient to allowfurther reaction between the functional groups of the intermediateprepolymer and the NCO groups in the aliphatic isocyanate is from about60° C. to about 90° C., preferably about 70° C. to about 80° C. For thepurposes of this aspect of the invention, any of the aromatic andaliphatic isocyanate-containing components discussed earlier may beused.

Once formed, the prepolymer preferably has about 3 percent to about 20percent free isocyanate monomer (NCO groups). In one embodiment, the NCOcontent of the prepolymer is about 4 percent and 10 percent. In anotherembodiment, the prepolymer has about 5 percent to about 7 percent NCOgroups. For example, the prepolymer may have about 6 to about 6.5percent NCO groups.

Without being bound to any particular theory, the number of unreactedNCO groups in the prepolymer may be varied to control such factors asthe speed of the reaction, the resultant hardness of the composition,and the like. In this aspect of the invention, the prepolymer may bestripped of the free isocyanate monomer. For example, after stripping,the prepolymer may contain about 1 percent or less free isocyanatemonomer. In another embodiment, the prepolymer contains about 0.5percent by weight or less of free isocyanate monomer.

Skilled artisans are also aware that the various properties of the golfball and golf ball components, e.g., hardness, may be controlled byadjusting the ratio of prepolymer to curing agent, which is a functionof the NCO content of the prepolymer, discussed above, and molecularweight of the curing agent. For example, the ratio of a prepolymer with6 percent unreacted NCO groups cured with 1,4-butanediol is 15.6:1,whereas the ratio of the same prepolymer cured with4,4′-bis-(sec-butylamino)-dicyclohexylmethane is 4.36:1. The ratio ofprepolymer to curing agent for the purposes of this invention ispreferably from about 0.5:1 to about 16:1. Those of ordinary skill inthe art would be aware that the ratio should be adjusted to maximizeresiliency depending on the type of layer formed from the composition ofthe invention. For example, when forming a cover from the composition ofthe invention, the ratio of the prepolymer to curative may be about1:0.95.

Likewise, the ratio of prepolymer to curing agent plays a role indetermining whether the compositions is thermoset or thermoplastic. Forexample, prepolymers crosslinked with a curing agent with 1:1stoichiometry are thermoplastic in nature. Thermoset polyurethanes, onthe other hand, are generally produced when the ratio of prepolymer tocuring agent is less than 1. For example, the composition may bethermoset when the prepolymer to secondary diamine curing agent is1:0.95.

Because the selection of curing agent determines whether a compositionof the invention will be thermoplastic or thermoset, the method ofmolding the compositions of the invention onto the ball also will varydepending on the type of composition. For example, thermoplasticpolyurea compositions of the present invention may be used to makethermoplastic pellets that can be molded onto the ball by injectionmolding or compression molding. Thermoset polyurea compositions may becast onto the ball. In addition, both the thermoplastic and thermosetpolyurea compositions of the present invention also may be formed aroundthe core using reaction injection molding (RIM) and liquid injectionmolding (LIM) techniques.

The compositions of the invention may have a material hardness of about6 Shore D to about 30 Shore D. In one embodiment, the material hardnessof the composition of the invention is about 10 Shore D to about 20Shore D. In another embodiment, the material hardness is about 8 Shore Dto about 16 Shore D, preferably about 8 Shore D to about 14 Shore D. Instill another embodiment, the material hardness is about 10 Shore D toabout 14 Shore D, preferably about 10 Shore D to about 12 Shore D.

Additives

Additional materials conventionally included in polyurethane and/orpolyurea compositions may be added to the prepolymers or curedcompositions of the invention. These additional materials include, butare not limited to, catalysts, wetting agents, coloring agents, opticalbrighteners, crosslinking agents, whitening agents such as TiO₂ and ZnO,UV absorbers, hindered amine light stabilizers, defoaming agents,processing aids, surfactants, and other conventional additives. Forexample, wetting additives may be added to the modified curative blendsof the invention to more effectively disperse the pigment(s). Suitablewetting agents are available from Byk-Chemle and Crompton Corporation,among others.

Antioxidants, stabilizers, softening agents, plasticizers, includinginternal and external plasticizers, impact modifiers, foaming agents,density-adjusting fillers, reinforcing materials, and compatibilizersmay also be added to any composition of the invention. Those of ordinaryskill in the art are aware of the purpose of these additives and theamounts that should be employed to fulfill those purposes.

For example, a catalyst may also be employed to modify the reaction ratebetween the prepolymer and the curing agent. Suitable catalysts include,but are not limited to bismuth catalyst; zinc octoate; stannous octoate;tin catalysts such as di-butyltin dilaurate (DABCO® T-12 manufactured byAir Products and Chemicals, Inc.), di-butyltin diacetate (DABCO® T-1);stannous octoate (DABCO® T-9); tin (II) chloride, tin (IV) chloride,di-butyltin dimethoxide (FASCAT8-4211),dimethyl-bis[1-oxonedecyl)oxy]stannane (FORMEZ® UL-28), di-n-octyltinbis-isooctyl mercaptoacetate (FORMEZ® UL-29); amine catalysts such astriethylenediamine (DABCO® 33-LV), triethylamine, and tributylamine;organic acids such as oleic acid and acetic acid; delayed catalysts suchas POLYCAT™ SA-1, POLYCAT™ SA-2, POLYCAT™, and the like; and mixturesthereof.

The catalyst is preferably added in an amount sufficient to catalyze thereaction of the components in the reactive mixture. In one embodiment,the catalyst is present in an amount from about 0.001 percent to about 5percent by weight of the composition. For example, when using a tincatalyst, such as di-butyltin dilaurate, the catalyst is preferablypresent in an amount from about 0.005 percent to about 1 percent. Inanother embodiment, the catalyst is present in an amount of about 0.05weight percent or greater. In another embodiment, the catalyst ispresent in an amount of about 0.5 weight percent or greater.

Use of low levels of tin catalysts, typically from about 0 to about 0.04weight percent of the total composition, requires high temperatures toachieve a suitable reaction rate, which may result in degradation of theprepolymer. Increasing the amount of catalysts to unconventional highlevels enables the reduction in process temperatures while retainingcomparable cure stages. Use of the higher catalyst level also allows themixing speeds to be reduced. Thus, in one embodiment, the tin catalystis present in an amount from about 0.01 percent to about 0.55 percent byweight of the composition. In another embodiment, about 0.05 percent toabout 0.4 percent of tin catalyst is present in the composition. In yetanother embodiment, the tin catalyst is present in an amount from about0.1 percent to about 0.25 percent.

Without being bound to any particular theory, when used with aprepolymer containing urea linkages, a catalyst such as di-butyltindilaurate inhibits or slows down the cure rate. However, when used witha prepolymer containing urethane linkages, di-butyltin dilaurateaccelerates the reaction rate. One of ordinary skill in the art would beable to select the type and amount of catalyst best suited for theparticular type of composition formed according to the invention.

Density-Adjusting Filler(s)

Fillers may be added to the compositions of the invention to affectrheological and mixing properties, the specific gravity (i.e.,density-modifying fillers), the modulus, the tear strength,reinforcement, and the like. The fillers are generally inorganic, andsuitable fillers include numerous metals, metal oxides and salts, suchas zinc oxide and tin oxide, as well as barium sulfate, zinc sulfate,calcium carbonate, zinc carbonate, barium carbonate, clay, tungsten,tungsten carbide, an array of silicas, regrind (recycled core materialtypically ground to about 30 mesh particle), high-Mooney-viscosityrubber regrind, and mixtures thereof.

For example, the compositions of the invention can be reinforced byblending with a wide range of density-adjusting fillers, e.g., ceramics,glass spheres (solid or hollow, and filled or unfilled), and fibers,inorganic particles, and metal particles, such as metal flakes, metallicpowders, oxides, and derivatives thereof, as is known to those withskill in the art. The selection of such filler(s) is dependent upon thetype of golf ball desired, i.e., one-piece, two-piece, multi-component,or wound, as will be more fully detailed below. Generally, the fillerwill be inorganic, having a density of greater than 4 g/cc, and will bepresent in amounts between about 5 and about 65 weight percent based onthe total weight of the polymer components included in the layer(s) inquestion. Examples of useful fillers include zinc oxide, barium sulfate,calcium oxide, calcium carbonate, and silica, as well as other knowncorresponding salts and oxides thereof.

Fillers may also be used to modify the weight of the core or at leastone additional layer for specialty balls, e.g., a lower weight ball ispreferred for a player having a low swing speed.

Blowing or Foaming Agent(s)

The compositions of the invention may be foamed by the addition of theat least one physical or chemical blowing or foaming agent. The use of afoamed polymer allows the golf ball designer to adjust the density ormass distribution of the ball to adjust the angular moment of inertia,and, thus, the spin rate and performance of the ball. Foamed materialsalso offer a potential cost savings due to the reduced use of polymericmaterial.

Blowing or foaming agents useful include, but are not limited to,organic blowing agents, such as azobisformamide; azobisisobutyronitrile;diazoaminobenzene; N,N-dimethyl-N,N-dinitroso terephthalamide;N,N-dinitrosopentamethylene-tetramine; benzenesulfonyl-hydrazide;benzene-1,3-disulfonyl hydrazide; diphenylsulfon-3-3, disulfonylhydrazide; 4,4′-oxybis benzene sulfonyl hydrazide; p-toluene sulfonylsemicarbizide; barium azodicarboxylate; butylamine nitrile; nitroureas;trihydrazino triazine; phenyl-methyl-uranthan; p-sulfonhydrazide;peroxides; and inorganic blowing agents such as ammonium bicarbonate andsodium bicarbonate. A gas, such as air, nitrogen, carbon dioxide, etc.,can also be injected into the composition during the injection moldingprocess.

Additionally, a foamed composition of the present invention may beformed by blending microspheres with the composition either during orbefore the molding process. Polymeric, ceramic, metal, and glassmicrospheres are useful in the invention, and may be solid or hollow andfilled or unfilled. In particular, microspheres up to about 1000micrometers in diameter are useful. Furthermore, the use of liquidnitrogen for foaming, as disclosed in U.S. Pat. No. 6,386,992, which isincorporated by reference herein, may produce highly uniform foamedcompositions for use in the present invention.

Either injection molding or compression molding may be used to form alayer or a core including a foamed polymeric material. For example, acomposition of the present invention can be thermoformed and, thus, canbe compression molded. For compression molded grafted metallocenecatalyzed polymer blend layers, half-shells may be made by injectionmolding a grafted metallocene catalyzed polymer blend in a conventionalhalf-shell mold or by compression molding sheets of foamed graftedmetallocene catalyzed polymer. The half-shells are placed about apreviously formed center or core, cover, or mantle layer, and theassembly is introduced into a compression molding machine, andcompression molded at about 250° F. to 400° F. The molded balls are thencooled while still in the mold, and finally removed when the layer ofgrafted metallocene catalyzed polymer blend is hard enough to be handledwithout deforming. Additional core, mantle, and cover layers are thenmolded onto the previously molded layers, as needed, until a completeball is formed.

Light Stabilizers and Pigments

As discussed above, there are numerous ways to attain light stabilityover time, including using only saturated components and incorporatingUV absorbers and light stabilizers. For example, the addition of UVabsorbers and light stabilizers to any of the above unsaturatedcompositions is recommended to prevent significant yellowing and mayalso help to maintain the tensile strength, elongation, and colorstability in compositions including only saturated components. The useof light stabilizers may also assist in preventing cover surfacefractures due to photodegradation in both types of compositions. As usedherein, the term “light stabilizer” may be understood to includehindered amine light stabilizers, ultraviolet (UV) absorbers, andantioxidants.

Suitable light stabilizers include, but are not limited to, TINUVIN®292, TINUVIN® 328, TINUVIN® 213, TINUVIN® 765, TINUVIN® 770 and TINUVIN®622. TINUVIN® products are available from Ciba Specialty Chemicals ofTarrytown, N.Y. In one embodiment, the light stabilizer is UV absorberTINUVIN® 328, which is useful with aromatic compounds. In anotherembodiment, hindered amine light stabilizer TINUVIN® 765 is used witharomatic or aliphatic compounds. In addition, TINUVIN® 292 may also beused with the aromatic or aliphatic compositions of the invention.

In addition, as discussed above, dyes, as well as optical brightenersand fluorescent pigments may also be included in the golf ball coversproduced with polymers formed according to the present invention. Forexample, white dispersions may be added to a cover formulationcontaining aromatic components to combat the effects of discolorationdue to the carbon-carbon double bonds. Such additional ingredients maybe added in any amounts that will achieve their desired purpose.

Composition Blends

Other polymeric materials suitable for blending with the compositions ofthe invention include castable thermoplastics, cationic and anionicurethane ionomers and urethane epoxies, polyurethane ionomers, polyureaionomers, epoxy resins, polyethylenes, polyamides and polyesters,polycarbonates, polyacrylin, siloxanes and epoxy resins or their blends,and mixtures thereof. One of ordinary skill in the art would be wellaware of methods to blend the polymeric materials with the compositionof the invention.

Examples of suitable urethane ionomers are disclosed in U.S. Pat. No.5,692,974, the disclosure of which is hereby incorporated by referencein its entirety. Other examples of suitable polyurethanes are describedin U.S. Pat. No. 5,334,673, the entire disclosure of which isincorporated by reference herein. Examples of suitable polyureas used toform the polyurea ionomer listed above are discussed in U.S. Pat. No.5,484,870. In particular, the polyureas of U.S. Pat. No. 5,484,870 areprepared by reacting a polyisocyanate and a polyamine curing agent toyield polyurea, which are distinct from the polyureas of the presentinvention which are formed from a polyurea prepolymer and curing agent.Examples of suitable polyurethanes cured with epoxy group containingcuring agents are disclosed in U.S. Pat. No. 5,908,358. The disclosuresof the above patents are incorporated herein by reference in theirentirety.

Acid Functionalization of Compositions

The compositions of the invention may also be acid functionalized toimprove adhesion to other components or layers as disclosed in U.S. Pat.No. 6,610,812, which is incorporated by reference herein in itsentirety. The acid functional group is preferably based on a sulfonicgroup (HSO₃), carboxylic group (HCO₂), phosphoric acid group (H₂PO₃), ora combination thereof. More than one type of acid functional group maybe incorporated into the composition. In one embodiment, the acidfunctionality is achieved by incorporating the acid group(s) into theisocyanate-containing component or the isocyanate-reactive component.For example, the isocyanate-containing component and an acid functionalgroup containing compound, such as those described in U.S. Pat. Nos.4,956,438 and 5,071,578, the disclosures of which are incorporatedherein by reference in their entirety, may be reacted prior to formingthe prepolymer.

The acid group(s) may also be incorporated during a post-polymerizationreaction, wherein the acid functional group(s) is introduced or attachedto the cured polyurea or polyurea-polyurethane. Moreover, the acidfunctional polyurea or polyurea-polyurethanes made by way ofcopolymerization as described above may be further incorporated withadditional acid functional groups through such post-polymerizationreactions. Suitable agents to incorporate acid functional groups ontothe polyurea or polyurethane and methods for making are described inU.S. Pat. No. 6,207,784, the entire disclosure of which is incorporatedby reference herein.

One of ordinary skill in the art would be aware of other ways to preparethe acid functional polyurea or polyurethane. For example, a combinationof the embodiments described above may be used as described in U.S. Pat.No. 5,661,207, the disclosure of which is incorporated by reference inits entirety herein.

Golf Ball Construction

Golf Ball Core Layer(s)

The cores of the golf balls formed according to the invention may besolid, semi-solid, hollow, fluid-filled or powder-filled, one-piece ormulti-component cores. The term “semi-solid” as used herein refers to apaste, a gel, or the like. Any core material known to one of ordinaryskill in that art is suitable for use in the golf balls of theinvention. Suitable core materials include thermoset materials, such asrubber, styrene butadiene, polybutadiene, isoprene, polyisoprene,trans-isoprene, as well as thermoplastics such as ionomer resins,polyamides or polyesters, and thermoplastic and thermoset polyurethaneelastomers. As mentioned above, the compositions of the presentinvention may be used to form a core of a golf ball.

In the alternative, the golf ball core is formed from a compositionincluding a base rubber (natural, synthetic, or a combination thereof),a crosslinking agent, and a filler. In another embodiment, the golf ballcore is formed from a reaction product that includes a cis-to-transcatalyst, a resilient polymer component having polybutadiene, a freeradical source, and optionally, a crosslinking agent, a filler, or both.Various combinations of polymers, cis-to-trans catalysts, fillers,crosslinkers, and a source of free radicals, such as those disclosed inco-pending and co-assigned U.S. Pat. No. 6,998,445, the entiredisclosure of which is incorporated by reference herein, may be used toform the reaction product. Although this polybutadiene reaction productis discussed in a section pertaining to core compositions, the presentinvention also contemplates the use of the reaction product to form atleast a portion of any component of a golf ball.

As used herein, the terms core and center are generally usedinterchangeably to reference the innermost component of the ball. Insome embodiments, however, the term “center” is used when there aremultiple core layers, i.e., a center and an outer core layer.

To obtain a higher resilience and lower compression, a high-molecularweight polybutadiene with a cis-isomer content preferably greater thanabout 40 percent is converted to increase the percentage of trans-isomercontent at any point in the golf ball or portion thereof. In oneembodiment, the cis-isomer is present in an amount of greater than about70 percent, preferably greater than about 80 percent, and morepreferably greater than about 90 percent of the total polybutadienecontent. In still another embodiment, the cis-isomer is present in anamount of greater than about 95 percent, and more preferably greaterthan about 96 percent, of the total polybutadiene content.

A low amount of 1,2-polybutadiene isomer (“vinyl-polybutadiene”) isdesired in the initial polybutadiene, and the reaction product. In oneembodiment, the vinyl polybutadiene isomer content is less than about 7percent, preferably less than about 4 percent, and more preferably lessthan about 2 percent.

The polybutadiene material may have an absolute molecular weight ofgreater than about 200,000. In one embodiment, the polybutadienemolecular weight is greater than about 250,000, and more preferably fromabout 300,000 to 500,000. In another embodiment, the polybutadienemolecular weight is about 400,000 or greater. It is preferred that thepolydispersity of the material is no greater than about 2, morepreferably no greater than 1.8, and even more preferably no greater than1.6.

In one embodiment, the polybutadiene has a Mooney viscosity greater thanabout 20, preferably greater than about 30, and more preferably greaterthan about 40. Mooney viscosity is typically measured according to ASTMD-1646. In another embodiment, the Mooney viscosity of the polybutadieneis greater than about 35, and preferably greater than about 50. In yetanother embodiment, the Mooney viscosity is about 120 or less. Forexample, the Mooney viscosity of the unvulcanized polybutadiene may befrom about 40 to about 120. In one embodiment, the Mooney viscosity isabout 40 to about 80. In another embodiment, the Mooney viscosity isfrom about 45 to about 60, more preferably from about 45 to about 55.

In one embodiment, the center composition includes at least one rubbermaterial having a resilience index of at least about 40. In anotherembodiment, the resilience index of the at least one rubber material isat least about 50.

Examples of desirable polybutadiene rubbers include BUNA® CB22 and BUNA®CB23, commercially available from Bayer of Akron, Ohio; UBEPOL® 360L andUBEPOL® 150L, commercially available from UBE Industries of Tokyo,Japan; CARIFLEX® BCP820, CARIFLEX® BCP824, CARIFLEX® BR1220,commercially available from Shell of Houston, Tex.; and KINEX®7245 andKINEX® 7665, commercially available from Goodyear of Akron, Ohio. Ifdesired, the polybutadiene can also be mixed with other elastomers knownin the art such as natural rubber, polyisoprene rubber and/orstyrene-butadiene rubber in order to modify the properties of the core.

Without being bound by any particular theory, it is believed that thecis-to-trans catalyst component, in conjunction with the free radicalsource, acts to convert a percentage of the polybutadiene polymercomponent from the cis- to the trans-conformation. Thus, thecis-to-trans conversion preferably includes the presence of acis-to-trans catalyst, such as an organosulfur or metal-containingorganosulfur compound, a substituted or unsubstituted aromatic organiccompound that does not contain sulfur or metal, an inorganic sulfidecompound, an aromatic organometallic compound, or mixtures thereof.

As used herein, “cis-to-trans catalyst” means any component or acombination thereof that will convert at least a portion of cis-isomerto trans-isomer at a given temperature. The cis-to-trans catalystcomponent may include one or more cis-to-trans catalysts describedherein, but typically includes at least one organosulfur component, aGroup VIA component, an inorganic sulfide, or a combination thereof. Inone embodiment, the cis-to-trans catalyst is a blend of an organosulfurcomponent and an inorganic sulfide component or a Group VIA component.

As used herein when referring to the invention, the term “organosulfurcompound(s)” or “organosulfur component(s),” refers to any compoundcontaining carbon, hydrogen, and sulfur. As used herein, the term“sulfur component” means a component that is elemental sulfur, polymericsulfur, or a combination thereof. It should be further understood that“elemental sulfur” refers to the ring structure of S₈ and that“polymeric sulfur” is a structure including at least one additionalsulfur relative to the elemental sulfur.

The cis-to-trans catalyst is typically present in an amount sufficientto produce the reaction product so as to increase thetrans-polybutadiene isomer content to contain from about 5 percent to 70percent trans-isomer polybutadiene based on the total resilient polymercomponent. It is preferred that the cis-to-trans catalyst is present inan amount sufficient to increase the trans-polybutadiene isomer contentat least about 15 percent, more preferably at least about 20 percent,and even more preferably at least about 25 percent.

Therefore, the cis-to-trans catalyst is preferably present in an amountfrom about 0.1 to about 25 parts per hundred of the total resilientpolymer component. As used herein, the term “parts per hundred”, alsoknown as “pph”, is defined as the number of parts by weight of aparticular component present in a mixture, relative to 100 parts byweight of the total polymer component. Mathematically, this can beexpressed as the weight of an ingredient divided by the total weight ofthe polymer, multiplied by a factor of 100. In one embodiment, thecis-to-trans catalyst is present in an amount from about 0.1 to about 12pph of the total resilient polymer component. In another embodiment, thecis-to-trans catalyst is present in an amount from about 0.1 to about 10pph of the total resilient polymer component. In yet another embodiment,the cis-to-trans catalyst is present in an amount from about 0.1 toabout 8 pph of the total resilient polymer component. In still anotherembodiment, the cis-to-trans catalyst is present in an amount from about0.1 to about 5 pph of the total resilient polymer component. The lowerend of the ranges stated above also may be increased if it is determinedthat 0.1 pph does not provide the desired amount of conversion. Forinstance, the amount of the cis-to-trans catalyst is present may beabout 0.5 or more, 0.75 or more, 1.0 or more, or even 1.5 or more.

Suitable organosulfur components for use in the invention include, butare not limited to, at least one of diphenyl disulfide; 4,4′-ditolyldisulfide; 2,2′-benzamido diphenyl disulfide;bis(2-aminophenyl)disulfide; bis(4-aminophenyl)disulfide;bis(3-aminophenyl)disulfide; 2,2′-bis(4-aminonaphthyl)disulfide;2,2′-bis(3-aminonaphthyl)disulfide; 2,2′-bis(4-aminonaphthyl)disulfide;2,2′-bis(5-aminonaphthyl)disulfide; 2,2′-bis(6-aminonaphthyl)disulfide;2,2′-bis(7-aminonaphthyl)disulfide; 2,2′-bis(8-aminonaphthyl)disulfide;1,1′-bis(2-aminonaphthyl)disulfide; 1,1′-bis(3-aminonaphthyl)disulfide;1,1′-bis(3-aminonaphthyl)disulfide; 1,1′-bis(4-aminonaphthyl)disulfide;1,1′-bis(5-aminonaphthyl)disulfide; 1,1′-bis(6-aminonaphthyl)disulfide;1,1′-bis(7-aminonaphthyl)disulfide; 1,1′-bis(8-aminonaphthyl)disulfide;1,2′-diamino-1,2′-dithiodinaphthalene;2,3′-diamino-1,2′-dithiodinaphthalene; bis(4-chlorophenyl)disulfide;bis(2-chlorophenyl)disulfide; bis(3-chlorophenyl)disulfide;bis(4-bromophenyl)disulfide; bis(2-bromophenyl)disulfide;bis(3-bromophenyl)disulfide; bis(4-fluorophenyl)disulfide;bis(4-iodophenyl)disulfide; bis(2,5-dichlorophenyl)disulfide;bis(3,5-dichlorophenyl)disulfide; bis(2,4-dichlorophenyl)disulfide;bis(2,6-dichlorophenyl)disulfide; bis(2,5-dibromophenyl)disulfide;bis(3,5-dibromophenyl)disulfide; bis(2-chloro-5-bromophenyl)disulfide;bis(2,4,6-trichlorophenyl)disulfide;bis(2,3,4,5,6-pentachlorophenyl)disulfide; bis(4-cyanophenyl)disulfide;bis(2-cyanophenyl)disulfide; bis(4-nitrophenyl)disulfide;bis(2-nitrophenyl)disulfide; 2,2′-dithiobenzoic ethyl;2,2′-dithiobenzoic methyl; 2,2′-dithiobenzoic acid; 4,4′-dithiobenzoicethyl; bis(4-acetylphenyl)disulfide; bis(2-acetylphenyl)disulfide;bis(4-formylphenyl)disulfide; bis(4-carbamoylphenyl)disulfide;1,1′-dinaphthyl disulfide; 2,2′-dinaphthyl disulfide; 1,2′-dinaphthyldisulfide; 2,2′-bis(1-chlorodinaphthyl)disulfide;2,2′-bis(1-bromonaphthyl)disulfide; 1,1′-bis(2-chloronaphthyl)disulfide;2,2′-bis(1-cyanonaphtyl)disulfide; 2,2′-bis(1-acetylnaphthyl)disulfide;and the like; or a mixture thereof. Most preferred organosulfurcomponents include diphenyl disulfide, 4,4′-ditolyl disulfide, or amixture thereof, especially 4,4′-ditolyl disulfide. In one embodiment,the at least one organosulfur component is substantially free of metal.As used herein, the term “substantially free of metal” means less thanabout 10 weight percent, preferably less than about 5 weight percent,more preferably less than about 3 weight percent, even more preferablyless than about 1 weight percent, and most preferably less than about0.01 weight percent. Suitable substituted or unsubstituted aromaticorganic components that do not include sulfur or a metal include, butare not limited to, diphenyl acetylene, azobenzene, or a mixturethereof. The aromatic organic group preferably ranges in size from C₆ toC₂₀, and more preferably from C₆ to C₁₀.

In one embodiment, the organosulfur cis-to-trans catalyst is present inthe reaction product in an amount from about 0.5 pph or greater. Inanother embodiment, the cis-to-trans catalyst including a organosulfurcomponent is present in the reaction product in an amount from about 0.6pph or greater. In yet another embodiment, the cis-to-trans catalystincluding a organo sulfur component is present in the reaction productin an amount from about 1.0 pph or greater. In still another embodiment,the cis-to-trans catalyst including a organosulfur component is presentin the reaction product in an amount from about 2.0 pph or greater.

Suitable metal-containing organosulfur components include, but are notlimited to, cadmium, copper, lead, and tellurium analogs ofdiethyldithiocarbamate, diamyldithiocarbamate, anddimethyldithiocarbamate, or mixtures thereof. In one embodiment, themetal-containing organosulfur cis-to-trans catalyst is present in thereaction product in an amount from about 1.0 pph or greater. In anotherembodiment, the cis-to-trans catalyst including a Group VIA component ispresent in the reaction product in an amount from about 2.0 pph orgreater. In yet another embodiment, the cis-to-trans catalyst includinga Group VIA component is present in the reaction product in an amountfrom about 2.5 pph or greater. In still another embodiment, thecis-to-trans catalyst including a Group VIA component is present in thereaction product in an amount from about 3.0 pph or greater.

The organosulfur component may also be an halogenated organosulfurcompound. Halogenated organosulfur compounds include, but are notlimited to those having the following general formula:

where R₁-R₅ can be C₁-C₈ alkyl groups; halogen groups; thiol groups(—SH), carboxylated groups; sulfonated groups; and hydrogen; in anyorder; and also pentafluorothiophenol; 2-fluorothiophenol;3-fluorothiophenol; 4-fluorothiophenol; 2,3-fluorothiophenol;2,4-fluorothiophenol; 3,4-fluorothiophenol; 3,5-fluorothiophenol2,3,4-fluorothiophenol; 3,4,5-fluorothiophenol;2,3,4,5-tetrafluorothiophenol; 2,3,5,6-tetrafluorothiophenol;4-chlorotetrafluorothiophenol; pentachlorothiophenol;2-chlorothiophenol; 3-chlorothiophenol; 4-chlorothiophenol;2,3-chlorothiophenol; 2,4-chlorothiophenol; 3,4-chlorothiophenol;3,5-chlorothiophenol; 2,3,4-chlorothiophenol; 3,4,5-chlorothiophenol;2,3,4,5-tetrachlorothiophenol; 2,3,5,6-tetrachlorothiophenol;pentabromothiophenol; 2-bromothiophenol; 3-bromothiophenol;4-bromothiophenol; 2,3-bromothiophenol; 2,4-bromothiophenol;3,4-bromothiophenol; 3,5-bromothiophenol; 2,3,4-bromothiophenol;3,4,5-bromothiophenol; 2,3,4,5-tetrabromothiophenol;2,3,5,6-tetrabromothiophenol; pentaiodothiophenol; 2-iodothiophenol;3-iodothiophenol; 4-iodothiophenol; 2,3-iodothiophenol;2,4-iodothiophenol; 3,4-iodothiophenol; 3,5-iodothiophenol;2,3,4-iodothiophenol; 3,4,5-iodothiophenol; 2,3,4,5-tetraiodothiophenol;2,3,5,6-tetraiodothiophenoland; and their metal salts, e.g., zinc,magnesium, lithium, calcium, potassium, manganese, nickel, and the like.Preferably, the halogenated organosulfur compound ispentachlorothiophenol, which is commercially available in neat form orunder the tradename STRUKTOL®, a clay-based carrier containing thesulfur compound pentachlorothiophenol loaded at 45 percent (correlatingto 2.4 parts PCTP). STRUKTOL® is commercially available from StruktolCompany of America of Stow, Ohio. PCTP is commercially available in neatform from eChinachem of San Francisco, Calif. and in the salt form fromeChinachem of San Francisco, Calif. Most preferably, the halogenatedorganosulfur compound is the zinc salt of pentachlorothiophenol, whichis commercially available from eChinachem of San Francisco, Calif. Thehalogenated organosulfur compounds of the present invention arepreferably present in an amount greater than about 2.2 pph, morepreferably between about 2.3 pph and about 5 pph, and most preferablybetween about 2.3 and about 4 pph.

The cis-to-trans catalyst may also include a Group VIA component. Asused herein, the terms “Group VIA component” or “Group VIA element” meana component that includes a sulfur component, selenium, tellurium, or acombination thereof. Elemental sulfur and polymeric sulfur arecommercially available from, e.g., Elastochem, Inc. of Chardon, Ohio.Exemplary sulfur catalyst compounds include PB(RM-S)-80 elemental sulfurand PB(CRST)-65 polymeric sulfur, each of which is available fromElastochem, Inc. An exemplary tellurium catalyst under the tradenameTELLOY and an exemplary selenium catalyst under the tradename VANDEX areeach commercially available from RT Vanderbilt of Norwalk, Conn.

In one embodiment, the cis-to-trans catalyst including a Group VIAcomponent is present in the reaction product in an amount from about0.25 pph or greater. In another embodiment, the cis-to-trans catalystincluding a Group VIA component is present in the reaction product in anamount from about 0.5 pph or greater. In yet another embodiment, thecis-to-trans catalyst including a Group VIA component is present in thereaction product in an amount from about 1.0 pph or greater.

Suitable inorganic sulfide components include, but are not limited totitanium sulfide, manganese sulfide, and sulfide analogs of iron,calcium, cobalt, molybdenum, tungsten, copper, selenium, yttrium, zinc,tin, and bismuth. In one embodiment, the cis-to-trans catalyst includingan inorganic sulfide component is present in the reaction product in anamount from about 0.5 pph or greater. In another embodiment, thecis-to-trans catalyst including a Group VIA component is present in thereaction product in an amount from about 0.75 pph or greater. In yetanother embodiment, the cis-to-trans catalyst including a Group VIAcomponent is present in the reaction product in an amount from about 1.0pph or greater. When a reaction product includes a blend of cis-to-transcatalysts including an organosulfur component and an inorganic sulfidecomponent, the organosulfur component is preferably present in an amountfrom about 0.5 or greater, preferably 1.0 or greater, and morepreferably about 1.5 or greater and the inorganic sulfide component ispreferably present in an amount from about 0.5 pph or greater,preferably 0.75 pph or greater, and more preferably about 1.0 pph orgreater.

A substituted or unsubstituted aromatic organic compound may also beincluded in the cis-to-trans catalyst. In one embodiment, the aromaticorganic compound is substantially free of metal. Suitable substituted orunsubstituted aromatic organic components include, but are not limitedto, components having the formula (R₁)_(x)—R₃-M-R₄—(R₂)_(y), wherein R₁and R₂ are each hydrogen or a substituted or unsubstituted C₁₋₂₀ linear,branched, or cyclic alkyl, alkoxy, or alkylthio group, or a single,multiple, or fused ring C₆ to C₂₄ aromatic group; x and y are each aninteger from 0 to 5; R₃ and R₄ are each selected from a single,multiple, or fused ring C₆ to C₂₄ aromatic group; and M includes an azogroup or a metal component. R₃ and R₄ are each preferably selected froma C₆ to C₁₀ aromatic group, more preferably selected from phenyl,benzyl, naphthyl, benzamido, and benzothiazyl. R₁ and R₂ are eachpreferably selected from a substituted or unsubstituted C₁₋₁₀ linear,branched, or cyclic alkyl, alkoxy, or alkylthio group or a C₆ to C₁₀aromatic group. When R₁, R₂, R₃, or R₄, are substituted, thesubstitution may include one or more of the following substituentgroups: hydroxy and metal salts thereof; mercapto and metal saltsthereof; halogen; amino, nitro, cyano, and amido; carboxyl includingesters, acids, and metal salts thereof; silyl; acrylates and metal saltsthereof; sulfonyl or sulfonamide; and phosphates and phosphites. When Mis a metal component, it may be any suitable elemental metal availableto those of ordinary skill in the art. Typically, the metal will be atransition metal, although preferably it is tellurium or selenium.

A free-radical source, often alternatively referred to as a free-radicalinitiator, is preferred in the rubber-based core composition. Thefree-radical source is typically a peroxide, and preferably an organicperoxide, which decomposes during the cure cycle. Suitable free-radicalsources include organic peroxide compounds, such as di-t-amyl peroxide,di(2-t-butyl-peroxyisopropyl)benzene peroxideor,-bis(t-butylperoxy)diisopropylbenzene,1,1-bis(t-butylperoxy)-3,3,5-trimethylcyclohexane or1,1-di(t-butylperoxy) 3,3,5-trimethyl cyclohexane, dicumyl peroxide,di-t-butyl peroxide, 2,5-di-(t-butylperoxy)-2,5-dimethyl hexane,n-butyl-4,4-bis(t-butylperoxy)valerate, lauryl peroxide, benzoylperoxide, t-butyl hydroperoxide, and the like, and any mixture thereof.

Other examples include, but are not limited to, VAROX® 231XL and Varox®DCP-R, commercially available from Elf Atochem of Philadelphia, Pa.;PERKADOX® BC and PERKADOX® 14, commercially available from Akzo Nobel ofChicago, Ill.; and ELASTOCHEM® DCP-70, commercially available from RheinChemie of Trenton, N.J. It is well known that peroxides are available ina variety of forms having different activity. The activity is typicallydefined by the “active oxygen content.” For example, PERKADOX® BCperoxide is 98 percent active and has an active oxygen content of 5.8percent, whereas PERKADOX® DCP-70 is 70 percent active and has an activeoxygen content of 4.18 percent. The peroxide is may be present in anamount greater than about 0.1 parts per hundred of the total resilientpolymer component, preferably about 0.1 to 15 parts per hundred of theresilient polymer component, and more preferably about 0.2 to 5 partsper hundred of the total resilient polymer component. If the peroxide ispresent in pure form, it is preferably present in an amount of at leastabout 0.25 pph, more preferably between about 0.35 pph and about 2.5pph, and most preferably between about 0.5 pph and about 2 pph.

Peroxides are also available in concentrate form, which are well-knownto have differing activities, as described above. In this case, ifconcentrate peroxides are employed in the present invention, one skilledin the art would know that the concentrations suitable for pureperoxides are easily adjusted for concentrate peroxides by dividing bythe activity. For example, 2 pph of a pure peroxide is equivalent 4 pphof a concentrate peroxide that is 50 percent active (i.e., 2 divided by0.5=4).

In one embodiment, the amount of free radical source is about 5 pph orless, but also may be about 3 pph or less. In another embodiment, theamount of free radical source is about 2.5 pph or less. In yet anotherembodiment, the amount of free radical source is about 2 pph or less. Instill another embodiment, the amount of free radical source is about 1pph or less preferably about 0.75 pph or less.

Those of ordinary skill in the art should understand that the presenceof certain cis-to-trans catalysts according to the invention be moresuited for a larger amount of free-radical source, such as the amountsdescribed herein, compared to conventional cross-linking reactions. Thefree radical source may alternatively or additionally be one or more ofan electron beam, UV or gamma radiation, x-rays, or any other highenergy radiation source capable of generating free radicals. A skilledartisan is aware that heat often facilitates initiation of thegeneration of free radicals.

In one embodiment, the ratio of the free radical source to thecis-to-trans catalyst is about 10 or less, but also may be about 5 orless. Additionally, the ratio of the free radical source to thecis-to-trans catalyst may be from about 4 or less, but also may be about2 or less, and also may be about 1 or less. In another embodiment, theratio of the free radical source to the cis-to-trans catalyst is about0.5 or less, preferably about 0.4 or less. In yet another embodiment,the free radical source cis-to-trans catalyst ratio is greater thanabout 1.0. In still another embodiment, the free radical sourcecis-to-trans catalyst is about 1.5 or greater, preferably about 1.75 orgreater.

Crosslinkers may be included to increase the hardness of the reactionproduct. Suitable crosslinking agents include one or more metallic saltsof unsaturated fatty acids having 3 to 8 carbon atoms, such as acrylicor methacrylic acid, or monocarboxylic acids, such as zinc, calcium, ormagnesium acrylate salts, and the like, and mixtures thereof. Examplesinclude, but are not limited to, one or more metal salt diacrylates,dimethacrylates, and monomethacrylates, wherein the metal is magnesium,calcium, zinc, aluminum, sodium, lithium, or nickel. Preferred acrylatesinclude zinc acrylate, zinc diacrylate, zinc methacrylate, zincdimethacrylate, and mixtures thereof. In one embodiment, zincmethacrylate is used in combination with the zinc salt ofpentachlorothiophenol. The crosslinking agent must be present in anamount sufficient to crosslink a portion of the chains of polymers inthe resilient polymer component. For example, the desired compressionmay be obtained by adjusting the amount of crosslinking. This may beachieved, for example, by altering the type and amount of crosslinkingagent, a method well-known to those of ordinary skill in the art. Thecrosslinking agent is typically present in an amount greater than about0.1 percent of the polymer component, preferably from about 10 to 50percent of the polymer component, more preferably from about 10 to 40percent of the polymer component.

In one embodiment, the crosslinking agent is present in an amountgreater than about 10 parts per hundred (“pph”) parts of the basepolymer, preferably from about 20 to about 40 pph of the base polymer,more preferably from about 25 to about 35 pph of the base polymer. Whenan organosulfur is selected as the cis-to-trans catalyst, zincdiacrylate may be selected as the crosslinking agent and is present inan amount of less than about 25 pph.

It is to be understood that when elemental sulfur or polymeric sulfur isincluded in the cis-to-trans catalyst, an accelerator may be used toimprove the performance of the cis-to-trans catalyst. Suitableaccelerators include, but are not limited to, sulfenamide, such asN-oxydiethylene 2-benzothiazole-sulfenamide, thiazole, such asbenzothiazyl disulfide, dithiocarbamate, such as bismuthdimethyldithiocarbamate, thiuram, such as tetrabenzyl thiuram disulfide,xanthate, such as zinc isopropyl xanthate, thiadiazine, thiourea, suchas trimethylthiourea, guanadine, such as N,N′-di-ortho-tolylguanadine,or aldehyde-amine, such as a butyraldehyde-aniline condensation product,or mixtures thereof.

Typically, antioxidants are included in conventional golf ball corecompositions because antioxidants are included in the materials suppliedby manufacturers of compounds used in golf ball cores. Without beingbound to any particular theory, higher amounts of antioxidant in thereaction product may result in less trans-isomer content because theantioxidants consume at least a portion of the free radical source.Thus, even with high amounts of the free radical source in the reactionproduct described previously, such as for example about 3 pph, an amountof antioxidant greater than about 0.3 pph may significantly reduce theeffective amount of free radicals that are actually available to assistin a cis-to-trans conversion.

Because it is believed that the presence of antioxidants in thecomposition may inhibit the ability of free radicals to adequatelyassist in the cis-to-trans conversion, one way to ensure sufficientamounts of free radicals are provided for the conversion is to increasethe initial levels of free radicals present in the composition so thatsufficient amounts of free radicals remain after interaction withantioxidants in the composition. Thus, the initial amount of freeradicals provided in the composition may be increased by at least about10 percent, and more preferably are increased by at least about 25percent so that the effective amount of remaining free radicalssufficient to adequately provide the desired cis-to-trans conversion.Depending on the amount of antioxidant present in the composition, theinitial amount of free radicals may be increased by at least 50 percent,100 percent, or an even greater amount as needed. As discussed below,selection of the amount of free radicals in the composition may bedetermined based on a desired ratio of free radicals to antioxidant.

Another approach is to reduce the levels of or eliminate antioxidants inthe composition. For instance, the reaction product of the presentinvention may be substantially free of antioxidants, thereby achievinggreater utilization of the free radicals toward the cis-to-transconversion. As used herein, the term “substantially free” generallymeans that the polybutadiene reaction product includes less than about0.3 pph of antioxidant, preferably less than about 0.1 pph ofantioxidant, more preferably less than about 0.05 pph of antioxidant,and most preferably about 0.01 pph or less antioxidant.

The amount of antioxidant has been shown herein to have a relationshipwith the amount of trans-isomer content after conversion. For example, apolybutadiene reaction product with 0.5 pph of antioxidant cured at 335°F. for 11 minutes results in about 15 percent trans-isomer content at anexterior surface of the center and about 13.4 percent at an interiorlocation after the conversion reaction. In contrast, the samepolybutadiene reaction product substantially free of antioxidantsresults in about 32 percent trans-isomer content at an exterior surfaceand about 21.4 percent at an interior location after the conversionreaction.

In one embodiment, the ratio of the free radical source to antioxidantis greater than about 10. In another embodiment, the ratio of the freeradical source to antioxidant is greater than about 25, preferablygreater than about 50. In yet another embodiment, the free radicalsource-antioxidant ratio is about 100 or greater. In still anotherembodiment, the free radical source-antioxidant ratio is about 200 orgreater, preferably 250 or greater, and more preferably about 300 orgreater.

If the reaction product is substantially free of antioxidants, theamount of the free radical source is preferably about 3 pph or less. Inone embodiment, the free radical source is present in an amount of about2.5 pph or less, preferably about 2 pph or less. In yet anotherembodiment, the amount of the free radical source in the reactionproduct is about 1.5 pph or less, preferably about 1 pph or less. Instill another embodiment, the free radical source is present is anamount of about 0.75 pph or less.

When the reaction product contains about 0.1 pph or greater antioxidant,the free radical source is preferably present in an amount of about 1pph or greater. In one embodiment, when the reaction product has about0.1 pph or greater antioxidant, the free radical source is present in anamount of about 2 pph or greater. In another embodiment, the freeradical source is present in an amount of about 2.5 pph or greater whenthe antioxidant is present in an amount of about 0.1 pph or greater.

In one embodiment, when the reaction product contains greater than about0.05 pph of antioxidant, the free radical source is preferably presentin an amount of about 0.5 pph or greater. In another embodiment, whenthe reaction product has greater than about 0.05 pph of antioxidant, thefree radical source is present in an amount of about 2 pph or greater.In yet another embodiment, the free radical source is present in anamount of about 2.5 pph or greater when the antioxidant is present in anamount of about 0.05 pph or greater.

Additional materials conventionally included in golf ball compositionsmay be added to rubber-based core compositions. These additionalmaterials include, but are not limited to, density-adjusting fillers,coloring agents, reaction enhancers, crosslinking agents, whiteningagents, UV absorbers, hindered amine light stabilizers, defoamingagents, processing aids, and other conventional additives. Stabilizers,softening agents, plasticizers, including internal and externalplasticizers, impact modifiers, foaming agents, excipients, reinforcingmaterials and compatibilizers can also be added to any composition ofthe invention. All of these materials, which are well known in the art,are added for their usual purpose in typical amounts.

For example, the fillers discussed above with respect to thecompositions of the invention may be added to the rubber-based corecompositions to affect rheological and mixing properties, the specificgravity (i.e., density-modifying fillers), the modulus, the tearstrength, reinforcement, and the like. Fillers may also be used tomodify the weight of the core, e.g., a lower weight ball is preferredfor a player having a low swing speed.

As discussed above, it may be preferable to convert cis-isomer totrans-isomer in polybutadiene core materials. Thus, in one embodiment,the amount of trans-isomer content after conversion is at least about 10percent or greater, while in another it is about 12 percent or greater.In another embodiment, the amount of trans-isomer content is about 15percent or greater after conversion. In yet another embodiment, theamount of trans-isomer content after conversion is about 20 percent orgreater, and more preferably is about 25 percent or greater. In stillanother embodiment, the amount of trans-isomer content after conversionis about 30 percent or greater, and preferably is about 32 percent orgreater. The amount of trans-isomer after conversion also may be about35 percent or greater, about 38 percent or greater, or even about 40percent or greater. In yet another embodiment, the amount oftrans-isomer after conversion may be about 42 percent or greater, oreven about 45 percent or greater.

The cured portion of the component including the reaction product of theinvention may have a first amount of trans-isomer polybutadiene at aninterior location and a second amount of trans-isomer polybutadiene atan exterior surface location. In one embodiment, the amount oftrans-isomer at the exterior surface location is greater than the amountof trans-isomer at an interior location. As will be further illustratedby the examples provided herein, the difference in trans-isomer contentbetween the exterior surface and the interior location after conversionmay differ depending on the cure cycle and the ratios of materials usedfor the conversion reaction. For example, it is also possible that thesedifferences can reflect a center with greater amounts of trans-isomer atthe interior portion than at the exterior portion.

The exterior portion of the center may have amounts of trans-isomerafter conversion in the amounts already indicated previously herein,such as in amounts about 10 percent or greater, about 12 percent orgreater, about 15 percent or greater, and the like, up to and includingamounts that are about 45 percent or greater as stated above. Forexample, in one embodiment of the invention, the polybutadiene reactionproduct may contain between about 35 percent to 60 percent of thetrans-isomer at the exterior surface of a center portion. Anotherembodiment has from about 40 percent to 50 percent of trans-isomer atthe exterior surface of a center portion. In one embodiment, thereaction product contains about 45 percent trans-isomer polybutadiene atthe exterior surface of a center portion. In one embodiment, thereaction product at the center of the solid center portion may thencontain at least about 20 percent less trans-isomer than is present atthe exterior surface, preferably at least about 30 percent lesstrans-isomer, or at least about 40 percent less trans-isomer. In anotherembodiment, the amount of trans-isomer at the interior location is atleast about 6 percent less than is present at the exterior surface,preferably at least about 10 percent less than the second amount.

The gradient between the interior portion of the center and the exteriorportion of the center may vary. In one embodiment, the difference intrans-isomer content between the exterior and the interior afterconversion is about 3 percent or greater, while in another embodimentthe difference may be about 5 percent or greater. In another embodiment,the difference between the exterior surface and the interior locationafter conversion is about 10 percent or greater, and more preferably isabout 20 percent or greater. In yet another embodiment, the differencein trans-isomer content between the exterior surface and the interiorlocation after conversion may be about 5 percent or less, about 4percent or less, and even about 3 percent or less. In yet anotherembodiment, the difference between the exterior surface and the interiorlocation after conversion is less than about 1 percent.

The polybutadiene reaction product material preferably has a hardness ofat least about 15 Shore A, more preferably between about 30 Shore A and80 Shore D, and even more preferably between about 50 Shore A and 60Shore D. In addition, the specific gravity is typically greater thanabout 0.7, preferably greater than about 1, for the golf ballpolybutadiene material. Moreover, the polybutadiene reaction productpreferably has a flexural modulus of from about 500 psi to 300,000 psi,preferably from about 2,000 to 200,000 psi.

The desired loss tangent in the polybutadiene reaction product should beless than about 0.15 at −60° C. and less than about 0.05 at 30° C. whenmeasured at a frequency of 1 Hz and a 1 percent strain. In oneembodiment, the polybutadiene reaction product material preferably has aloss tangent below about 0.1 at −50° C., and more preferably below about0.07 at −50° C.

To produce golf balls having a desirable compressive stiffness, thedynamic stiffness of the polybutadiene reaction product material shouldbe less than about 50,000 N/m at −50° C. Preferably, the dynamicstiffness should be between about 10,000 and 40,000 N/m at −50° C., morepreferably, the dynamic stiffness should be between about 20,000 and30,000 N/m at −50° C.

In one embodiment, the reaction product has a first dynamic stiffnessmeasured at −50° C. that is less than about 130 percent of a seconddynamic stiffness measured at 0° C. In another embodiment, the firstdynamic stiffness is less than about 125 percent of the second dynamicstiffness. In yet another embodiment, the first dynamic stiffness isless than about 110 percent of the second dynamic stiffness.

Golf Ball Intermediate Layer(s)

When the golf ball of the present invention includes an intermediatelayer, such as an inner cover layer or outer core layer, i.e., anylayer(s) disposed between the inner core and the outer cover of a golfball, this layer can include any materials known to those of ordinaryskill in the art including thermoplastic and thermosetting materials. Inone embodiment, the intermediate layer is formed, at least in part, fromthe composition of the invention.

The intermediate layer may also likewise include one or morehomopolymeric or copolymeric materials, such as:

-   -   (1) Vinyl resins, such as those formed by the polymerization of        vinyl chloride, or by the copolymerization of vinyl chloride        with vinyl acetate, acrylic esters or vinylidene chloride;    -   (2) Polyolefins, such as polyethylene, polypropylene,        polybutylene and copolymers such as ethylene methylacrylate,        ethylene ethylacrylate, ethylene vinyl acetate, ethylene        methacrylic or ethylene acrylic acid or propylene acrylic acid        and copolymers and homopolymers produced using a single-site        catalyst or a metallocene catalyst;    -   (3) Polyurethanes, such as those prepared from polyols and        diisocyanates or polyisocyanates and those disclosed in U.S.        Pat. No. 5,334,673;    -   (4) Polyureas, such as those disclosed in U.S. Pat. No.        5,484,870;    -   (5) Polyamides, such as poly(hexamethylene adipamide) and others        prepared from diamines and dibasic acids, as well as those from        amino acids such as poly(caprolactam), and blends of polyamides        with SURLYN, polyethylene, ethylene copolymers,        ethyl-propylene-non-conjugated diene terpolymer, and the like;    -   (6) Acrylic resins and blends of these resins with poly vinyl        chloride, elastomers, and the like;    -   (7) Thermoplastics, such as urethanes; olefinic thermoplastic        rubbers, such as blends of polyolefins with        ethylene-propylene-non-conjugated diene terpolymer; block        copolymers of styrene and butadiene, isoprene or        ethylene-butylene rubber; or copoly(ether-amide), such as PEBAX,        sold by Atofina Chemicals, Inc. of Philadelphia, Pa. and the        thermoplastic compositions disclosed in U.S. Pat. No. 5,688,191,        the entire disclosure of which is incorporated by reference        herein;    -   (8) Polyphenylene oxide resins or blends of polyphenylene oxide        with high impact polystyrene as sold under the trademark NORYL        by General Electric Company of Pittsfield, Mass.;    -   (9) Thermoplastic polyesters, such as polyethylene        terephthalate, polybutylene terephthalate, polyethylene        terephthalate/glycol modified and elastomers sold under the        trademarks HYTREL by E.I. DuPont de Nemours & Co. of Wilmington,        Del., and LOMOD by General Electric Company of Pittsfield,        Mass.;    -   (10) Blends and alloys, including polycarbonate with        acrylonitrile butadiene styrene, polybutylene terephthalate,        polyethylene terephthalate, styrene maleic anhydride,        polyethylene, elastomers, and the like, and polyvinyl chloride        with acrylonitrile butadiene styrene or ethylene vinyl acetate        or other elastomers; and    -   (11) Blends of thermoplastic rubbers with polyethylene,        propylene, polyacetal, nylon, polyesters, cellulose esters, and        the like.

In one embodiment, the intermediate layer includes polymers, such asethylene, propylene, butene-1 or hexene-1 based homopolymers orcopolymers including functional monomers, such as acrylic andmethacrylic acid and fully or partially neutralized ionomer resins andtheir blends, methyl acrylate, methyl methacrylate homopolymers andcopolymers, imidized, amino group containing polymers, polycarbonate,reinforced polyamides, polyphenylene oxide, high impact polystyrene,polyether ketone, polysulfone, poly(phenylene sulfide),acrylonitrile-butadiene, acrylic-styrene-acrylonitrile, poly(ethyleneterephthalate), poly(butylene terephthalate), poly(ethylene vinylalcohol), poly(tetrafluoroethylene) and their copolymers includingfunctional comonomers, and blends thereof.

As briefly mentioned above, the intermediate layer may include ionomericmaterials, such as ionic copolymers of ethylene and an unsaturatedmonocarboxylic acid, which are available under the trademark SURLYN® ofE.I. DuPont de Nemours & Co., of Wilmington, Del., or IOTEK® or ESCOR®of Exxon. These are copolymers or terpolymers of ethylene andmethacrylic acid or acrylic acid totally or partially neutralized, i.e.,from about 1 to about 100 percent, with salts of zinc, sodium, lithium,magnesium, potassium, calcium, manganese, nickel or the like. In oneembodiment, the carboxylic acid groups are neutralized from about 10percent to about 100 percent. The carboxylic acid groups may alsoinclude methacrylic, crotonic, maleic, fumaric or itaconic acid. Thesalts are the reaction product of an olefin having from 2 to 10 carbonatoms and an unsaturated monocarboxylic acid having 3 to 8 carbon atoms.

The intermediate layer may also include at least one ionomer, such asacid-containing ethylene copolymer ionomers, including E/X/Y terpolymerswhere E is ethylene, X is an acrylate or methacrylate-based softeningcomonomer present in about 0 to 50 weight percent and Y is acrylic ormethacrylic acid present in about 5 to 35 weight percent. In anotherembodiment, the acrylic or methacrylic acid is present in about 8 to 35weight percent, more preferably 8 to 25 weight percent, and mostpreferably 8 to 20 weight percent.

The ionomer also may include so-called “low acid” and “high acid”ionomers, as well as blends thereof. In general, ionic copolymersincluding up to about 15 percent acid are considered “low acid”ionomers, while those including greater than about 15 percent acid areconsidered “high acid” ionomers. For example, U.S. Pat. Nos. 6,506,130and 6,503,156 define low acid ionomers to include 16 weight percent orless acid content, whereas high acid ionomers are defined as containinggreater than about 16 weight percent acid. In one embodiment, theintermediate layer is formed from a blend of low acid ionomers. Forexample, an ionomeric composition suitable for the intermediate layermay be formed from a low acid sodium ionomer and a low acid lithiumionomer with acid levels between about 13 percent and 16 percent.

A low acid ionomer is believed to impart high spin. Thus, in oneembodiment, the intermediate layer includes a low acid ionomer where theacid is present in about 10 to 15 weight percent and optionally includesa softening comonomer, e.g., iso- or n-butylacrylate, to produce asofter terpolymer. The softening comonomer may be selected from thegroup consisting of vinyl esters of aliphatic carboxylic acids whereinthe acids have 2 to 10 carbon atoms, vinyl ethers wherein the alkylgroups contains 1 to 10 carbon atoms, and alkyl acrylates ormethacrylates wherein the alkyl group contains 1 to 10 carbon atoms.Suitable softening comonomers include vinyl acetate, methyl acrylate,methyl methacrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate,butyl methacrylate, or the like.

In another embodiment, the intermediate layer includes at least one highacid ionomer, for low spin rate and maximum distance. In this aspect,the acrylic or methacrylic acid is present in about 15 to about 35weight percent, making the ionomer a high modulus ionomer. In oneembodiment, the high modulus ionomer includes about 16 percent by weightof a carboxylic acid, preferably from about 17 percent to about 25percent by weight of a carboxylic acid, more preferably from about 18.5percent to about 21.5 percent by weight of a carboxylic acid. In somecircumstances, an additional comonomer such as an acrylate ester (i.e.,iso- or n-butylacrylate, etc.) can also be included to produce a softerterpolymer. The additional comonomer may be selected from the groupconsisting of vinyl esters of aliphatic carboxylic acids wherein theacids have 2 to 10 carbon atoms, vinyl ethers wherein the alkyl groupscontains 1 to 10 carbon atoms, and alkyl acrylates or methacrylateswherein the alkyl group contains 1 to 10 carbon atoms. Suitablesoftening comonomers include vinyl acetate, methyl acrylate, methylmethacrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate, butylmethacrylate, or the like.

Consequently, examples of a number of copolymers suitable for use toproduce the high modulus ionomers include, but are not limited to, highacid embodiments of an ethylene/acrylic acid copolymer, anethylene/methacrylic acid copolymer, an ethylene/itaconic acidcopolymer, an ethylene/maleic acid copolymer, an ethylene/methacrylicacid/vinyl acetate copolymer, an ethylene/acrylic acid/vinyl alcoholcopolymer, and the like.

In one embodiment, the intermediate layer may be formed from at leastone polymer containing α,β-unsaturated carboxylic acid groups, or thesalts thereof, that have been 100 percent neutralized by organic fattyacids. The organic acids are aliphatic, mono-functional (saturated,unsaturated, or multi-unsaturated) organic acids. Salts of these organicacids may also be employed. The salts of organic acids of the presentinvention include the salts of barium, lithium, sodium, zinc, bismuth,chromium, cobalt, copper, potassium, strontium, titanium, tungsten,magnesium, cesium, iron, nickel, silver, aluminum, tin, or calcium,salts of fatty acids, particularly stearic, behenic, erucic, oleic,linoleic, or dimerized derivatives thereof. It is preferred that theorganic acids and salts of the present invention be relativelynon-migratory (they do not bloom to the surface of the polymer underambient temperatures) and non-volatile (they do not volatilize attemperatures required for melt-blending).

The acid moieties of the highly-neutralized polymers (“HNP”), typicallyethylene-based ionomers, are preferably neutralized greater than about70 percent, more preferably greater than about 90 percent, and mostpreferably at least about 100 percent. The HNP's may be also be blendedwith a second polymer component, which, if containing an acid group, maybe neutralized in a conventional manner, by organic fatty acids, orboth. The second polymer component, which may be partially or fullyneutralized, preferably comprises ionomeric copolymers and terpolymers,ionomer precursors, thermoplastics, polyamides, polycarbonates,polyesters, polyurethanes, polyureas, thermoplastic elastomers,polybutadiene rubber, balata, metallocene-catalyzed polymers (graftedand non-grafted), single-site polymers, high-crystalline acid polymers,cationic ionomers, and the like.

In this embodiment, the acid copolymers can be described as E/X/Ycopolymers where E is ethylene, X is an α,β-ethylenically unsaturatedcarboxylic acid, and Y is a softening comonomer. In a preferredembodiment, X is acrylic or methacrylic acid and Y is a C₁₋₈ alkylacrylate or methacrylate ester. X is preferably present in an amountfrom about 1 to about 35 weight percent of the polymer, more preferablyfrom about 5 to about 30 weight percent of the polymer, and mostpreferably from about 10 to about 20 weight percent of the polymer. Y ispreferably present in an amount from about 0 to about 50 weight percentof the polymer, more preferably from about 5 to about 25 weight percentof the polymer, and most preferably from about 10 to about 20 weightpercent of the polymer.

The organic acids are aliphatic, mono-functional (saturated,unsaturated, or multi-unsaturated) organic acids. Salts of these organicacids may also be employed. The salts of organic acids of the presentinvention include the salts of barium, lithium, sodium, zinc, bismuth,chromium, cobalt, copper, potassium, strontium, titanium, tungsten,magnesium, cesium, iron, nickel, silver, aluminum, tin, or calcium,salts of fatty acids, particularly stearic, behenic, erucic, oleic,linoleic, or dimerized derivatives thereof. It is preferred that theorganic acids and salts of the present invention be relativelynon-migratory (they do not bloom to the surface of the polymer underambient temperatures) and non-volatile (they do not volatilize attemperatures required for melt-blending).

Thermoplastic polymer components, such as copolyetheresters,copolyesteresters, copolyetheramides, elastomeric polyolefins, styrenediene block copolymers and their hydrogenated derivatives,copolyesteramides, thermoplastic polyurethanes, such ascopolyetherurethanes, copolyesterurethanes, copolyureaurethanes,epoxy-based polyurethanes, polycaprolactone-based polyurethanes,polyureas, and polycarbonate-based polyurethanes fillers, and otheringredients, if included, can be blended in either before, during, orafter the acid moieties are neutralized.

Examples of these materials are disclosed in U.S. Patent ApplicationPublication Nos. 2001/0018375 and 2001/0019971, which are incorporatedherein in their entirety by express reference thereto.

The ionomer compositions may also include at least one graftedmetallocene catalyzed polymer. Blends of this embodiment may includeabout 1 pph to about 100 pph of at least one grafted metallocenecatalyzed polymer and about 99 pph to 0 pph of at least one ionomer,preferably from about 5 pph to about 90 pph of at least one graftedmetallocene catalyzed polymer and about 95 pph to about 10 pph of atleast one ionomer, more preferably from about 10 pph to about 75 pph ofat least one grafted metallocene catalyzed polymer and about 90 pph toabout 25 pph of at least one ionomer, and most preferably from about 10pph to about 50 pph of at least one grafted metallocene catalyzedpolymer and about 90 pph to about 50 pph of at least one ionomer. Wherethe layer is foamed, the grafted metallocene catalyzed polymer blendsmay be foamed during molding by any conventional foaming or blowingagent.

In another embodiment, the intermediate layer includes at least oneprimarily or fully non-ionomeric thermoplastic material. Suitablenon-ionomeric materials include polyamides and polyamide blends, graftedand non-grafted metallocene catalyzed polyolefins or polyamides,polyamide/ionomer blends, polyamide/nonionomer blends, polyphenyleneether/ionomer blends, and mixtures thereof. Examples of grafted andnon-grafted metallocene catalyzed polyolefins or polyamides,polyamide/ionomer blends, polyamide/nonionomer blends are disclosed inco-pending U.S. Pat. No. 6,800,690, the entire disclosure of which isincorporated by reference herein.

In one embodiment, polyamide homopolymers, such as polyamide 6,18 andpolyamide 6,36 are used alone, or in combination with other polyamidehomopolymers. In another embodiment, polyamide copolymers, such aspolyamide 6,10/6,36, are used alone, or in combination with otherpolyamide copolymers. Other examples of suitable polyamide homopolymersand copolymers include polyamide 4, polyamide 6, polyamide 7, polyamide11, polyamide 12 (manufactured as Rilsan AMNO by Atofina Chemicals, Inc.of Philadelphia, Pa.), polyamide 13, polyamide 4,6, polyamide 6,6,polyamide 6,9, polyamide 6,10, polyamide 6,12, polyamide 6,36, polyamide12,12, polyamide 13,13, polyamide 6/6,6, polyamide 6,6/6,10, polyamide6/6,T wherein T represents terephthalic acid, polyamide 6/6,6/6,10,polyamide 6,10/6,36, polyamide 66,6,18, polyamide 66,6,36, polyamide6/6,18, polyamide 6/6,36, polyamide 6/6,10/6,18, polyamide 6/6,10/6,36,polyamide 6,10/6,18, polyamide 6,12/6,18, polyamide 6,12/6,36, polyamide6/66/6,18, polyamide 6/66/6,36, polyamide 66/6,10/6,18, polyamide66/6,10/6,36, polyamide 6/6,12/6,18, polyamide 6/6,12/6,36, and mixturesthereof.

As mentioned above, any of the above polyamide homopolymer, copolymer,and homopolymer/copolymer blends may be optionally blended withionomers, nonionomer polymers, such as nonionomer thermoplasticpolymers, nonionomer thermoplastic copolymers, nonionomer TPEs, andmixtures thereof.

One specific example of a polyamide-nonionomer blend is apolyamide-metallocene catalyzed polymer blend. The blended compositionsmay include grafted and/or non-grafted metallocene catalyzed polymers.Grafted metallocene catalyzed polymers, functionalized with pendantgroups, such as maleic anhydride, and the like, are available inexperimental quantities from DuPont. Grafted metallocene catalyzedpolymers may also be obtained by subjecting a commercially availablenon-grafted metallocene catalyzed polymer to a post-polymerizationreaction involving a monomer and an organic peroxide to provide agrafted metallocene catalyzed polymer with the desired pendant group orgroups.

Another example of a polyamide-nonionomer blend is a polyamide andnon-ionic polymers produced using non-metallocene single-site catalysts.As used herein, the term “non-metallocene catalyst” or non-metallocenesingle-site catalyst” refers to a single-site catalyst other than ametallocene catalyst. Examples of suitable single-site catalyzedpolymers are disclosed in co-pending U.S. patent application Ser. No.09/677,871, of which the entire disclosure is incorporated by referenceherein.

Nonionomers suitable for blending with the polyamide include, but arenot limited to, block copoly(ester) copolymers, block copoly(amide)copolymers, block copoly(urethane) copolymers, styrene-based blockcopolymers, thermoplastic and elastomer blends wherein the elastomer isnot vulcanized (TEB), and thermoplastic and elastomer or rubber blendswherein the elastomer is dynamically vulcanized (TED). Other nonionomerssuitable for blending with polyamide to form an intermediate layercomposition include, but are not limited to, polycarbonate,polyphenylene oxide, imidized, amino group containing polymers, highimpact polystyrene (HIPS), polyether ketone, polysulfone, poly(phenylenesulfide), reinforced engineering plastics,acrylic-styrene-acrylonitrile, poly(tetrafluoroethylene), poly(butylacrylate), poly(4-cyanobutyl acrylate), poly(2-ethylbutyl acrylate),poly(heptyl acrylate), poly(2-methylbutyl acrylate), poly(3-methylbutylacrylate), poly(N-octadecylacrylamide), poly(octadecyl methacrylate),poly(4-dodecylstyrene), poly(4-tetradecylstyrene), poly(ethylene oxide),poly(oxymethylene), poly(silazane), poly(furan tetracarboxylic aciddiimide), poly(acrylonitrile), poly(methylstyrene), silicones, as wellas the classes of polymers to which they belong and their copolymersincluding functional comonomers, and blends thereof.

In one embodiment, the non-ionomeric materials have a hardness of about60 Shore D or greater and a flexural modulus of about 30,000 psi orgreater.

The intermediate layer may include a resilient polymer component, whichis preferably used as the majority of polymer in the intermediate layerto impart resilience in the cured state, and a reinforcing polymercomponent as a blend. Resilient polymers suitable for use in theintermediate layer include polybutadiene, polyisoprene,styrene-butadiene, styrene-propylene-diene rubber,ethylene-propylene-diene (EPDM), mixtures thereof, and the like,preferably having a high molecular weight of at least about 50,000 toabout 1,000,000. In one embodiment, the molecular weight is from about250,000 to about 750,000, and more preferably from about 200,000 toabout 400,000.

Golf Ball Cover(s)

The cover provides the interface between the ball and a club. Propertiesthat are desirable for the cover are good moldability, high abrasionresistance, high impact resistance, high tear strength, high resilience,and good mold release, among others. The cover layer may be formed, atleast in part, from the composition of the invention. In one embodiment,the compositions of the invention may be used to form at least one coverlayer of a golf ball of the present invention. For example, the coverlayer may be formed with the reaction product of anisocyanate-containing component and an isocyanate-reactive component,which may be cured with a curing agent. In one embodiment, the coverlayer is formed from a composition of the invention including aprepolymer of an aromatic diisocyanate and a polyol having between about5 percent and 7 percent free NCO that has been cured with a polyetherdiol.

The cover compositions may also be formed from or include one or morehomopolymeric or copolymeric materials, such as:

-   -   (1) Vinyl resins, such as those formed by the polymerization of        vinyl chloride, or by the copolymerization of vinyl chloride        with vinyl acetate, acrylic esters or vinylidene chloride;    -   (2) Polyolefins, such as polyethylene, polypropylene,        polybutylene and copolymers such as ethylene methylacrylate,        ethylene ethylacrylate, ethylene vinyl acetate, ethylene        methacrylic or ethylene acrylic acid or propylene acrylic acid,        and copolymers and homopolymers produced using a single-site        catalyst;    -   (3) Polyurethanes, thermoplastic or thermoset, saturated or        unsaturated, aliphatic or aromatic, acid functionalized, such as        those prepared from polyols or amines and diisocyanates or        polyisocyanates and those disclosed in U.S. Pat. No. 5,334,673        and U.S. patent application Ser. No. 10/072,395;    -   (4) Polyureas, thermoplastic or thermoset, saturated or        unsaturated, aliphatic or aromatic, acid functionalized, such as        those disclosed in U.S. Pat. No. 5,484,870 and U.S. patent        application Ser. No. 10/072,395;    -   (5) Polyamides, such as poly(hexamethylene adipamide) and others        prepared from diamines and dibasic acids, as well as those from        amino acids such as poly(caprolactam), reinforced polyamides,        and blends of polyamides with ionomers, polyethylene, ethylene        copolymers, ethyl-propylene-non-conjugated diene terpolymer, and        the like;    -   (6) Acrylic resins and blends of these resins with poly vinyl        chloride, elastomers, and the like;    -   (7) Thermoplastics, such as urethanes; olefinic thermoplastic        rubbers, such as blends of polyolefins with        ethylene-propylene-non-conjugated diene terpolymer; block        copolymers of styrene and butadiene, isoprene or        ethylene-butylene rubber; or copoly(ether-amide), such as PEBAX,        sold by Atofina Chemicals, Inc. of Philadelphia, Pa., or the        thermoplastic compositions disclosed in U.S. Pat. No. 5,688,191;    -   (8) Polyphenylene oxide resins or blends of polyphenylene oxide        with high impact polystyrene as sold under the trademark NORYL        by General Electric Company of Pittsfield, Mass.;    -   (9) Thermoplastic polyesters, such as polyethylene        terephthalate, polybutylene terephthalate, polyethylene        terephthalate/glycol modified and elastomers sold under the        trademarks HYTREL by E.I. DuPont de Nemours & Co. of Wilmington,        Del., and LOMOD by General Electric Company of Pittsfield,        Mass.;    -   (10) Ethylene, propylene, 1-butene or 1-hexene based        homopolymers or copolymers including functional monomers, such        as acrylic and methacrylic acid or fully or partially        neutralized ionomer resins, and their blends, methyl acrylate,        methyl methacrylate homopolymers and copolymers, low acid        ionomers, high acid ionomers, and blends thereof;    -   (11) Blends and alloys, including polycarbonate with        acrylonitrile butadiene styrene, polybutylene terephthalate,        polyethylene terephthalate, styrene maleic anhydride,        polyethylene, elastomers, and the like, and polyvinyl chloride        with acrylonitrile butadiene styrene or ethylene vinyl acetate        or other elastomers; and    -   (12) Blends of thermoplastic rubbers with polyethylene,        propylene, polyacetal, nylon, polyesters, cellulose esters, and        the like.

The cover may also be at least partially formed from the polybutadienereaction product discussed above with respect to the core.

As discussed elsewhere herein, the composition may be molded onto thegolf ball in any known manner, such as by casting, compression molding,injection molding, reaction injection molding, or the like. One skilledin the art would appreciate that the molding method used may bedetermined at least partially by the properties of the composition. Forexample, casting may be preferred when the material is thermoset,whereas compression molding or injection molding may be preferred forthermoplastic compositions.

Golf Ball Constructions

The compositions of the present invention may be used with any type ofball construction including, but not limited to, one-piece, two-piece,three-piece, and four-piece designs, a double core, a double cover, anintermediate layer(s), a multilayer core, and/or a multi-layer coverdepending on the type of performance desired of the ball. That is, thecompositions of the invention may be used in a core, intermediate layer,and/or cover of a golf ball, each of which may have a single layer ormultiple layers. As used herein, the term “multilayer” means at leasttwo layers.

As described above in the core section, a core may be a one-piece coreor a multilayer core, both of which may be solid, semi-solid, hollow,fluid-filled, or powder-filled. A multilayer core is one that has aninnermost component with an additional core layer or additional corelayers disposed thereon.

In addition, when the golf ball of the present invention includes anintermediate layer, this layer may be incorporated with a single ormultilayer cover, a single or multi-piece core, with both a single layercover and core, or with both a multilayer cover and a multilayer core.The intermediate layer may be an inner cover layer or outer core layer,or any other layer(s) disposed between the inner core and the outercover of a golf ball. As with the core, the intermediate layer may alsoinclude a plurality of layers. It will be appreciated that any number ortype of intermediate layers may be used, as desired.

For example, FIG. 1 shows a golf ball 1 having a core 2, at least oneintermediate layer 3, and a cover 4. In one embodiment, the golf ball ofFIG. 1 represents a core 2 of polybutadiene reaction material or otherconventional materials and a cover 4 including the composition of theinvention. In another embodiment, the core 2 of FIG. 1 may be liquidwhere a hollow spherical core shell is liquid filled. The intermediatelayer 3 may be formed of a conventional ionomer or the composition ofthe invention.

The intermediate layer may also be a tensioned elastomeric materialwound around a solid, semi-solid, hollow, fluid-filled, or powder-filledcenter. As used herein, the term “fluid” refers to a liquid or gas andthe term “semi-solid” refers to a paste, gel, or the like. A wound layermay be described as a core layer or an intermediate layer for thepurposes of the invention. As an example, the golf ball 1 of FIG. 1 mayinclude a core 2, a tensioned elastomeric layer 3 wound thereon, and acover layer 4. In particular, the golf ball 1 of FIG. 1 may have a core2 made of a polybutadiene reaction product, an intermediate layerincluding a tensioned elastomeric material 3 and cover 4 formed from thecomposition of the invention. In this aspect of the invention, thecomposition of the invention may be formed using an isocyanate-reactivecomponent having a hydrophobic backbone to create a more water resistantgolf ball. The tensioned elastomeric material may be formed of anysuitable material known to those of ordinary skill in the art. In oneembodiment, the composition of the invention is used to form thetensioned elastomeric material.

At least one layer of the ball may be a moisture barrier layer, such asthe ones described in U.S. Pat. No. 5,820,488, which is incorporated byreference herein. Any suitable film-forming material having a lowerwater vapor transmission rate than the other layers between the core andthe outer surface of the ball, i.e., cover, primer, and clear coat.Examples include, but are not limited to polyvinylidene chloride,vermiculite, and a polybutadiene reaction product with fluorine gas. Inone embodiment, the moisture barrier layer has a water vaportransmission rate that is sufficiently low to reduce the loss of COR ofthe golf ball by at least 5 percent if the ball is stored at 100° F. and70 percent relative humidity for six weeks as compared to the loss inCOR of a golf ball that does not include the moisture barrier, has thesame type of core and cover, and is stored under substantially identicalconditions.

Prior to forming the cover layer, the inner ball, i.e., the core and anyintermediate layers disposed thereon, may be surface treated to increasethe adhesion between the outer surface of the inner ball and the cover.Examples of such surface treatment may include mechanically orchemically abrading the outer surface of the subassembly. Additionally,the inner ball may be subjected to corona discharge, plasma treatment,silane dipping, or other chemical treatment methods known to those ofordinary skill in the art prior to forming the cover around it. Otherlayers of the ball, e.g., the core and the cover layers, also may besurface treated. Examples of these and other surface treatmenttechniques can be found in U.S. Pat. No. 6,315,915, which isincorporated by reference in its entirety.

The core or cover may include a plurality of layers, e.g., an innercover layer disposed about a golf ball center and an outer cover layerformed thereon. For example, FIG. 2 may represent a golf ball 5 having acore 6, an outer core layer or intermediate layer 7, a thin inner coverlayer 8, and a thin outer cover layer 9 disposed thereon. In particular,the core 6 and intermediate layer 7 may be formed of a polybutadienereaction material, the inner cover layer 8 formed of the composition ofthe invention or a conventional ionomeric material, and the outer coverlayer 9 formed of the composition of the invention or a conventionalcover material.

Furthermore, the compositions of the invention may be used to form agolf ball 10, shown in FIG. 3, having a large core 11 and a thin outercover layer 12. In one embodiment, the large core 11 is formed of apolybutadiene reaction material and the thin outer cover layer 12 isformed of the composition. In another embodiment, a thin inner coverlayer 13 is added between the large core 11 and the thin outer coverlayer 12.

While hardness gradients are typically used in a golf ball to achievecertain characteristics, the present invention also contemplates thecompositions of the invention being used in a golf ball with multiplecover layers having essentially the same hardness, wherein at least oneof the layers has been modified in some way to alter a property thataffects the performance of the ball. Such ball constructions aredisclosed in co-pending U.S. patent application Ser. No. 10/167,744,filed Jun. 13, 2002, entitled “Golf Ball with Multiple Cover Layers,”the entire disclosure of which is incorporated by reference herein.

In one such embodiment, both covers layers can be formed of the samematerial and have essentially the same hardness, but the layers aredesigned to have different coefficient of friction values. In anotherembodiment, the compositions of the invention are used in a golf ballwith multiple cover layers having essentially the same hardness, butdifferent rheological properties under high deformation. Another aspectof this embodiment relates to a golf ball with multiple cover layershaving essentially the same hardness, but different thicknesses tosimulate a soft outer cover over hard inner cover ball.

In another aspect of this concept, the cover layers of a golf ball haveessentially the same hardness, but different properties at high or lowtemperatures as compared to ambient temperatures. In particular, thisaspect of the invention is directed to a golf ball having multiple coverlayers wherein the outer cover layer composition has a lower flexuralmodulus at reduced temperatures than the inner cover layer, while thelayers retain the same hardness at ambient and reduced temperatures,which results in a simulated soft outer cover layer over a hard innercover layer feel. Certain polyureas may have a much more stable flexuralmodulus at different temperatures than ionomer resins and thus, could beused to make an effectively “softer” layer at lower temperatures than atambient or elevated temperatures.

Yet another aspect of this concept relates to a golf ball with multiplecover layers having essentially the same hardness, but differentproperties under wet conditions as compared to dry conditions.Wettability of a golf ball layer may be affected by surface roughness,chemical heterogeneity, molecular orientation, swelling, and interfacialtensions, among others. Thus, non-destructive surface treatments of agolf ball layer may aid in increasing the hydrophilicity of a layer,while highly polishing or smoothing the surface of a golf ball layer maydecrease wettability. U.S. Pat. Nos. 5,403,453 and 5,456,972 disclosemethods of surface treating polymer materials to affect the wettability,the entire disclosures of which are incorporated by reference herein. Inaddition, plasma etching, corona treating, and flame treating may beuseful surface treatments to alter the wettability to desiredconditions. Wetting agents may also be added to the golf ball layercomposition to modify the surface tension of the layer.

Thus, the differences in wettability of the cover layers according tothe invention may be measured by a difference in contact angle. Thecontact angles for a layer may be from about 1° (low wettability) toabout 180° (very high wettability). In one embodiment, the cover layershave contact angles that vary by about 1° or greater. In anotherembodiment, the contact angles of the cover layer vary by about 3° orgreater. In yet another embodiment, the contact angles of the coverlayers vary by about 5° or greater.

Other non-limiting examples of suitable types of ball constructions thatmay be used with the present invention include those described in U.S.Pat. Nos. 6,056,842, 5,688,191, 5,713,801, 5,803,831, 5,885,172,5,919,100, 5,965,669, 5,981,654, 5,981,658, and 6,149,535, as well as inPublication Nos. US2001/0009310 A1, US2002/0025862, and US2002/0028885.The entire disclosures of these patents and published patentapplications are incorporated by reference herein.

Forming the Layers

The golf balls of the invention may be formed using a variety ofapplication techniques such as compression molding, flip molding,injection molding, retractable pin injection molding, reaction injectionmolding (RIM), liquid injection molding (LIM), casting, vacuum forming,powder coating, flow coating, spin coating, dipping, spraying, and thelike. A method of injection molding using a split vent pin can be foundin U.S. Pat. No. 6,877,974. Examples of retractable pin injectionmolding may be found in U.S. Pat. Nos. 6,129,881, 6,235,230, and6,379,138. These molding references are incorporated in their entiretyby reference herein.

One skilled in the art would appreciate that the molding method used maybe determined at least partially by the properties of the composition.For example, casting, RIM, or LIM may be preferred when the material isthermoset, whereas compression molding or injection molding may bepreferred for thermoplastic compositions. Compression molding, however,may also be used for thermoset inner ball materials. For example, whencores are formed from a thermoset material, compression molding is aparticularly suitable method of forming the core, whereas when the coresare formed of a thermoplastic material, the cores may be injectionmolded. In addition, the intermediate layer may also be formed fromusing any suitable method known to those of ordinary skill in the art.For example, an intermediate layer may be formed by blow molding andcovered with a dimpled cover layer formed by injection molding,compression molding, casting, vacuum forming, powder coating, and thelike.

In addition, when layers are formed of the compositions of the inventionor other conventional polyurea and/or polyurethane compositions, thesematerials may be applied over an inner ball using a variety ofapplication techniques such as spraying, compression molding, dipping,spin coating, casting, or flow coating methods that are well known inthe art. Examples of forming polyurea and polyurethane materials aboutan inner ball are disclosed in U.S. Pat. Nos. 5,733,428, 5,006,297, and5,334,673, which are incorporated by reference in their entirety herein.In one embodiment, a combination of casting and compression molding canbe used to form a polyurethane or polyurea composition over an innerball. However, the method of forming covers according to the inventionis not limited to the use of these techniques; other methods known tothose skilled in the art may also be employed.

Prior to forming the cover layer, the inner ball, i.e., the core and anyintermediate layers disposed thereon, may be surface treated to furtherincrease the adhesion between the outer surface of the inner ball andthe cover. Examples of such surface treatment may include mechanicallyor chemically abrading the outer surface of the subassembly.Additionally, the inner ball may be subjected to corona discharge,plasma treatment, and/or silane dipping prior to forming the coveraround it. Other layers of the ball, e.g., the core, also may be surfacetreated. Examples of these and other surface treatment techniques can befound in U.S. Pat. No. 6,315,915, which is incorporated by reference inits entirety.

The methods discussed herein and other manufacturing methods for formingthe golf ball components of the present invention are also disclosed inU.S. Pat. Nos. 6,207,784 and 5,484,870, the disclosures of which areincorporated herein by reference in their entirety.

Dimples

The golf balls of the invention are preferably designed with certainflight characteristics in mind. The use of various dimple patterns andprofiles provides a relatively effective way to modify the aerodynamiccharacteristics of a golf ball. As such, the manner in which the dimplesare arranged on the surface of the ball can be by any available method.For instance, the ball may have an icosahedron-based pattern, such asdescribed in U.S. Pat. No. 4,560,168, or an octahedral-based dimplepatterns as described in U.S. Pat. No. 4,960,281. Alternatively, thedimple pattern can be arranged according to phyllotactic patterns, suchas described in U.S. Pat. No. 6,338,684, which is incorporated herein inits entirety.

Dimple patterns may also be based on Archimedean patterns including atruncated octahedron, a great rhombcuboctahedron, a truncateddodecahedron, and a great rhombicosidodecahedron, wherein the patternhas a non-linear or staggered parting line, as disclosed in U.S. Pat.No. 6,705,959, which is incorporated in its entirety by referenceherein. The golf balls of the present invention may also be covered withnon-circular shaped dimples, i.e., amorphous shaped dimples, asdisclosed in U.S. Pat. No. 6,409,615, which is incorporated in itsentirety by reference herein.

Dimple patterns that provide a high percentage of surface coverage arepreferred, and are well known in the art. For example, U.S. Pat. Nos.5,562,552, 5,575,477, 5,957,787, 5,249,804, and 4,925,193 disclosegeometric patterns for positioning dimples on a golf ball. In oneembodiment, the golf balls of the invention have a dimple coverage ofthe surface area of the cover of at least about 60 percent, preferablyat least about 65 percent, and more preferably at least 70 percent orgreater. Dimple patterns having even higher dimple coverage values mayalso be used with the present invention. Thus, the golf balls of thepresent invention may have a dimple coverage of at least about 75percent or greater, about 80 percent or greater, or even about 85percent or greater.

In addition, a tubular lattice pattern, such as the one disclosed inU.S. Pat. No. 6,290,615, which is incorporated by reference in itsentirety herein, may also be used with golf balls of the presentinvention. The golf balls of the present invention may also have aplurality of pyramidal projections disposed on the intermediate layer ofthe ball, as disclosed in U.S. Pat. No. 6,383,092, which is incorporatedin its entirety by reference herein. The plurality of pyramidalprojections on the golf ball may cover between about 20 percent to about80 of the surface of the intermediate layer.

In an alternative embodiment, the golf ball may have a non-planarparting line allowing for some of the plurality of pyramidal projectionsto be disposed about the equator. Such a golf ball may be fabricatedusing a mold as disclosed in U.S. patent application Ser. No.09/442,845, filed Nov. 18, 1999, entitled “Mold For A Golf Ball,” andwhich is incorporated in its entirety by reference herein. Thisembodiment allows for greater uniformity of the pyramidal projections.Several additional non-limiting examples of dimple patterns with varyingsizes of dimples are also provided in U.S. Pat. Nos. 6,358,161 and6,213,898, the entire disclosures of which are incorporated by referenceherein.

The total number of dimples on the ball, or dimple count, may varydepending such factors as the sizes of the dimples and the patternselected. In general, the total number of dimples on the ball preferablyis between about 100 to about 1000 dimples, although one skilled in theart would recognize that differing dimple counts within this range cansignificantly alter the flight performance of the ball. In oneembodiment, the dimple count is about 380 dimples or greater, but morepreferably is about 400 dimples or greater, and even more preferably isabout 420 dimples or greater. In another embodiment, the dimple count onthe ball is about 422 dimples. In some cases, it may be desirable tohave fewer dimples on the ball. In this regard, the dimple count on theball may range from about 240 to about 450, preferably about 252 toabout 440.

Dimple profiles revolving a catenary curve about its symmetrical axismay increase aerodynamic efficiency, provide a convenient way to alterthe dimples to adjust ball performance without changing the dimplepattern, and result in uniformly increased flight distance for golfersof all swing speeds. Thus, catenary curve dimple profiles, as disclosedin U.S. Pat. No. 6,796,912, which is incorporated in its entirety byreference herein, is contemplated for use with the golf balls of thepresent invention.

Golf Ball Post-Processing

The golf balls of the present invention may be painted, coated, orsurface treated for further benefits. For example, a golf ball of theinvention may be treated with a base resin paint composition or thecover composition may contain certain additives to achieve a desiredcolor characteristic. In one embodiment, the golf ball cover compositioncontains a fluorescent whitening agent, e.g., a derivative of7-triazinylamino-3-phenylcoumarin, to provide improved weatherresistance and brightness. An example of such a fluorescent whiteningagent is disclosed in U.S. Patent Publication No. 2002/0082358, which isincorporated by reference herein in its entirety.

Protective and decorative coating materials, as well as methods ofapplying such materials to the surface of a golf ball cover are wellknown in the golf ball art. Generally, such coating materials compriseurethanes, urethane hybrids, epoxies, polyesters and acrylics.

The coating layer(s) may be applied by any suitable method known tothose of ordinary skill in the art. For example, the coating layer(s)may be applied to the golf ball cover by an in-mold coating process,such as described in U.S. Pat. No. 5,849,168, which is incorporated inits entirety by reference herein. In addition, the golf balls of theinvention may be painted or coated with an ultraviolet curable/treatableink, by using the methods and materials disclosed in U.S. Pat. Nos.6,500,495, 6,248,804, and 6,099,415, the entire disclosures of which areincorporated by reference herein.

Any trademarks or other indicia that may be used with the presentinvention may be applied to the ball through a variety of methods knownto those of skill in the golf ball manufacturing art. In one embodiment,the indicia is stamped, i.e., pad-printed, on the outer surface of theball cover, and the stamped outer surface is then treated with at leastone clear coat to give the ball a glossy finish and protect the indiciastamped on the cover. In another embodiment, the indicia is applied tothe intended layer by ink-jet printing. And, if desired, more than onecoating layer can be used.

Golf Ball Properties

The properties such as hardness, modulus, core diameter, intermediatelayer thickness and cover layer thickness of the golf balls of thepresent invention have been found to effect play characteristics such asspin, initial velocity and feel of the present golf balls. For example,the flexural and/or tensile modulus of the intermediate layer arebelieved to have an effect on the “feel” of the golf balls of thepresent invention. It should be understood that the ranges herein aremeant to be intermixed with each other, i.e., the low end of one rangemay be combined with a high end of another range.

Component Dimensions

Dimensions of golf ball components, i.e., thickness and diameter, mayvary depending on the desired properties. For the purposes of theinvention, any layer thickness may be employed. Non-limiting examples ofthe various embodiments outlined above are provided here with respect tolayer dimensions.

The present invention relates to golf balls of any size. While USGAspecifications limit the size of a competition golf ball to more than1.68 inches in diameter, golf balls of any size can be used for leisuregolf play. The preferred diameter of the golf balls is from about 1.68inches to about 1.8 inches. The more preferred diameter is from about1.68 inches to about 1.76 inches. A diameter of from about 1.68 inchesto about 1.74 inches is most preferred, however diameters anywhere inthe range of from 1.7 to about 1.95 inches can be used. Preferably, theoverall diameter of the core and all intermediate layers is about 80percent to about 98 percent of the overall diameter of the finishedball.

The core may have a diameter ranging from about 0.09 inches to about1.65 inches. In one embodiment, the diameter of the core of the presentinvention is about 1.2 inches to about 1.630 inches. In anotherembodiment, the diameter of the core is about 1.3 inches to about 1.6inches, preferably from about 1.39 inches to about 1.6 inches, and morepreferably from about 1.5 inches to about 1.6 inches. In yet anotherembodiment, the core has a diameter of about 1.55 inches to about 1.65inches.

The core of the golf ball may also be extremely large in relation to therest of the ball. For example, in one embodiment, the core makes upabout 90 percent to about 98 percent of the ball, preferably about 94percent to about 96 percent of the ball. In this embodiment, thediameter of the core is preferably about 1.54 inches or greater,preferably about 1.55 inches or greater. In one embodiment, the corediameter is about 1.59 inches or greater. In another embodiment, thediameter of the core is about 1.64 inches or less.

When the core includes a center and an outer core layer, the center ispreferably about 0.9 inches or greater and the outer core layerpreferably has a thickness of about 0.1 inches or greater. In oneembodiment, the center has a diameter from about 0.09 inches to about1.2 inches and the outer core layer has a thickness from about 0.1inches to about 0.8 inches. In yet another embodiment, the centerdiameter is from about 0.095 inches to about 1.1 inches and the outercore layer has a thickness of about 0.20 inches to about 0.03 inches.

If the composition of the invention is used as an outer core layer, thecured thickness of the layer is preferably about 0.001 inches to about0.1 inches. In one embodiment, the outer core layer's cured thickness isabout 0.002 inches to about 0.05 inches. In another embodiment, thecured thickness of the outer core layer is about 0.003 inches to about0.03 inches.

The cover typically has a thickness to provide sufficient strength, goodperformance characteristics, and durability. In one embodiment, thecover thickness is from about 0.02 inches to about 0.35 inches. Inanother embodiment, the cover preferably has a thickness of about 0.02inches to about 0.12 inches, preferably about 0.1 inches or less, morepreferably about 0.07 inches or less. In yet another embodiment, theouter cover has a thickness from about 0.02 inches to about 0.07 inches.In still another embodiment, the cover thickness is about 0.05 inches orless, preferably from about 0.02 inches to about 0.05 inches. Forexample, the outer cover layer may be between about 0.02 inches andabout 0.045 inches, preferably about 0.025 inches to about 0.04 inchesthick. In one embodiment, the outer cover layer is about 0.03 inchesthick.

The range of thicknesses for an intermediate layer of a golf ball islarge because of the vast possibilities when using an intermediatelayer, i.e., as an outer core layer, an inner cover layer, a woundlayer, a moisture/vapor barrier layer. When used in a golf ball of theinvention, the intermediate layer, or inner cover layer, may have athickness about 0.3 inches or less. In one embodiment, the thickness ofthe intermediate layer is from about 0.002 inches to about 0.1 inches,preferably about 0.01 inches or greater. In one embodiment, thethickness of the intermediate layer is about 0.09 inches or less,preferably about 0.06 inches or less. In another embodiment, theintermediate layer thickness is about 0.05 inches or less, morepreferably about 0.01 inches to about 0.045 inches. In one embodiment,the intermediate layer, thickness is about 0.02 inches to about 0.04inches. In another embodiment, the intermediate layer thickness is fromabout 0.025 inches to about 0.035 inches. In yet another embodiment, thethickness of the intermediate layer is about 0.035 inches thick. Instill another embodiment, the inner cover layer is from about 0.03inches to about 0.035 inches thick. Varying combinations of these rangesof thickness for the intermediate and outer cover layers may be used incombination with other embodiments described herein.

The ratio of the thickness of the intermediate layer to the outer coverlayer is preferably about 10 or less, preferably from about 3 or less.In another embodiment, the ratio of the thickness of the intermediatelayer to the outer cover layer is about 1 or less. The core andintermediate layer(s) together form an inner ball preferably having adiameter of about 1.48 inches or greater for a 1.68-inch ball. In oneembodiment, the inner ball of a 1.68-inch ball has a diameter of about1.52 inches or greater. In another embodiment, the inner ball of a1.68-inch ball has a diameter of about 1.66 inches or less. In yetanother embodiment, a 1.72-inch (or more) ball has an inner balldiameter of about 1.50 inches or greater. In still another embodiment,the diameter of the inner ball for a 1.72-inch ball is about 1.70 inchesor less.

Hardness

Most golf balls consist of layers having different hardnesses, e.g.,hardness gradients, to achieve desired performance characteristics. Thepresent invention contemplates golf balls having hardness gradientsbetween layers, as well as those golf balls with layers having the samehardness.

It should be understood, especially to one of ordinary skill in the art,that there is a fundamental difference between “material hardness” and“hardness, as measured directly on a golf ball.” Material hardness isdefined by the procedure set forth in ASTM-D2240 and generally involvesmeasuring the hardness of a flat “slab” or “button” formed of thematerial of which the hardness is to be measured. The material hardnessof the compositions of the invention is addressed above.

Hardness, when measured directly on a golf ball (or other sphericalsurface) is a completely different measurement and, therefore, resultsin a different hardness value. This difference results from a number offactors including, but not limited to, ball construction (i.e., coretype, number of core and/or cover layers, etc.), ball (or sphere)diameter, and the material composition of adjacent layers. It shouldalso be understood that the two measurement techniques are not linearlyrelated and, therefore, one hardness value cannot easily be correlatedto the other. As such, the hardness of a golf ball component formed froma composition of the invention may differ significantly from thematerial hardness of the composition. In this regard, while thecomposition of the invention may have a material hardness of about 8Shore D to about 20 Shore D, a cover formed from a composition of theinvention may range from about 30 Shore D to about 60 Shore D. In oneembodiment, the material hardness is about 10 Shore D to about 14 ShoreD and the cover hardness is about 40 Shore D to about 55 Shore D. Inanother embodiment, the material hardness is about 10 Shore D to about12 Shore D and the cover hardness is less than about 50 Shore D.

The cores of the present invention may have varying hardnesses dependingon the particular golf ball construction. In one embodiment, the corehardness is at least about 15 Shore A, preferably about 30 Shore A, asmeasured on a formed sphere. In another embodiment, the core has ahardness of about 50 Shore A to about 90 Shore D. In yet anotherembodiment, the hardness of the core is about 80 Shore D or less.Preferably, the core has a hardness about 30 to about 65 Shore D, andmore preferably, the core has a hardness about 35 to about 60 Shore D.

The intermediate layer(s) of the present invention may also vary inhardness depending on the specific construction of the ball. In oneembodiment, the hardness of the intermediate layer is about 30 Shore Dor greater. In another embodiment, the hardness of the intermediatelayer is about 90 Shore D or less, preferably about 80 Shore D or less,and more preferably about 70 Shore D or less. For example, in oneembodiment, the intermediate layer may have a hardness of about 60 ShoreD or less. In yet another embodiment, the hardness of the intermediatelayer is about 50 Shore D or greater, preferably about 55 Shore D orgreater. In one embodiment, the intermediate layer hardness is fromabout 55 Shore D to about 65 Shore D. The intermediate layer may also beabout 65 Shore D or greater.

When the intermediate layer is intended to be harder than the corelayer, the ratio of the intermediate layer hardness to the core hardnesspreferably about 2 or less. In one embodiment, the ratio is about 1.8 orless. In yet another embodiment, the ratio is about 1.3 or less.

As with the core and intermediate layers, the cover hardness may varydepending on the construction and desired characteristics of the golfball. The ratio of cover hardness to inner ball hardness is a primaryvariable used to control the aerodynamics of a ball and, in particular,the spin of a ball. In general, the harder the inner ball, the greaterthe driver spin and the softer the cover, the greater the driver spin.

For example, when the intermediate layer is intended to be the hardestpoint in the ball, e.g., about 50 Shore D to about 75 Shore D, the covermaterial may have a hardness of about 30 Shore D or less, as measured onthe slab. In another embodiment, the cover itself has a hardness ofabout 30 Shore D or greater. In particular, the cover may be from about30 Shore D to about 70 Shore D. In one embodiment, the cover has ahardness of about 40 Shore D to about 65 Shore D, and in anotherembodiment, about 40 Shore to about 55 Shore D. In another aspect of theinvention, the cover has a hardness less than about 45 Shore D,preferably less than about 40 Shore D, and more preferably about 25Shore D to about 40 Shore D. In one embodiment, the cover has a hardnessfrom about 30 Shore D to about 40 Shore D.

The cover hardness may also be defined in terms of Shore C. For example,the cover may have a hardness of about 90 Shore C or less, preferablyabout 80 Shore C or less. In another embodiment, the cover has ahardness of about 75 Shore C or less.

In this aspect of the invention, i.e., when the outer cover layer issofter than the intermediate layer or inner cover layer, the ratio ofthe Shore D hardness of the outer cover material to the intermediatelayer material is about 0.9 or less, preferably about 0.85 or less, andmore preferably about 0.83 or less.

In yet another embodiment, the ratio is about 0.1 or less when the coverand intermediate layer materials have hardnesses that are substantiallythe same. When the hardness differential between the cover layer and theintermediate layer is not intended to be as significant, the cover mayhave a hardness of about 55 Shore D to about 65 Shore D. In thisembodiment, the ratio of the Shore D hardness of the outer cover to theintermediate layer is about 1.0 or less, preferably about 0.9 or less.

When a two-piece ball is constructed, the core is preferably harder thanthe cover. For example, the core hardness may range from about 40 ShoreD to about 80 Shore D, and the cover hardness may be from about 30 ShoreD to about 60 Shore D. In this type of construction, the ratio betweenthe cover hardness and the core hardness is preferably about 1 or less.In another embodiment, the ratio is about 0.98 or less.

Compression

Compression values are dependent on the diameter of the component beingmeasured. Atti compression is typically used to measure the compressionof a golf ball. As used herein, the terms “Atti compression” or“compression” are defined as the deflection of an object or materialrelative to the deflection of a calibrated spring, as measured with anAtti Compression Gauge, that is commercially available from AttiEngineering Corp. of Union City, N.J.

The Atti compression of the core, or portion of the core, of golf ballsprepared according to the invention is preferably less than about 100,more preferably less than about 95. In another embodiment, the corecompression is from about 50 to about 100, preferably from about 60 toabout 90. In yet another embodiment, the core compression is preferablygreater than about 60, and more preferably greater than about 65.

In this aspect of the invention, the compression of the cores may alsobe measured according to the Soft Center Deflection Index (“SCDI”). TheSCDI is a program change for the Dynamic Compression Machine (“DCM”)that allows determination of the pounds required to deflect a core 10percent of its diameter. The DCM is an apparatus that applies a load toa core or ball and measures the number of inches the core or ball isdeflected at measured loads. A crude load/deflection curve is generatedthat is fit to the Atti compression scale that results in a number beinggenerated that represents an Atti compression. The DCM does this via aload cell attached to the bottom of a hydraulic cylinder that istriggered pneumatically at a fixed rate (typically about 1.0 ft/s)towards a stationary core. Attached to the cylinder is an LVDT thatmeasures the distance the cylinder travels during the testing timeframe.A software-based logarithmic algorithm ensures that measurements are nottaken until at least five successive increases in load are detectedduring the initial phase of the test.

The SCDI is a slight variation of this set up. The hardware is the same,but the software and output has changed. With the SCDI, we are onlyinterested in the pounds of force required to deflect a core time theamount of inches. That amount of deflection is 10 percent of the corediameter. The DCM is triggered, the cylinder deflects the core by 10percent of its diameter, and the DCM reports back the pounds of forcerequired (as measured from the attached load cell) to deflect the coreby that amount. The value displayed is a single number in units ofpounds.

The core should have an SCDI compression less than about 160.Preferably, the core has an SCDI compression between about 40 and about160 and most preferably, the core has an SCDI compression between about60 and about 120. In one embodiment, the core has an SCDI compression ofabout 65 or greater, preferably about 70 or greater.

The golf balls of the invention preferably have an Atti compression ofabout 55 or greater, preferably from about 60 to about 120. In anotherembodiment, the Atti compression of the golf balls of the invention isat least about 70, preferably from about 80 to about 115. For example, apreferred golf ball of the invention may have a compression from about75 to about 90. In another embodiment, the compression of a dualcore/dual cover golf ball formed according to the invention is about 90to about 110, preferably about 95 to about 105.

Initial Velocity and COR

There is currently no USGA limit on the COR of a golf ball, but theinitial velocity of the golf ball cannot exceed 250±5 feet/second(ft/s). Thus, in one embodiment, the initial velocity is about 245 ft/sor greater and about 255 ft/s or greater. In another embodiment, theinitial velocity is about 250 ft/s or greater. In one embodiment, theinitial velocity is about 253 ft/s to about 254 ft/s. In yet anotherembodiment, the initial velocity is about 255 ft/s. While the currentrules on initial velocity require that golf ball manufacturers staywithin the limit, one of ordinary skill in the art would appreciate thatthe golf ball of the invention would readily convert into a golf ballwith initial velocity outside of this range. For example, a golf ball ofthe invention may be designed to have an initial velocity of about 220ft/s or greater, preferably about 225 ft/s or greater.

As a result, of the initial velocity limitation set forth by the USGA,the goal is to maximize COR without violating the 255 ft/s limit. TheCOR of a ball is measured by taking the ratio of the outbound or reboundvelocity to the incoming or inbound velocity. In a one-piece solid golfball, the COR will depend on a variety of characteristics of the ball,including its composition and hardness. For a given composition, CORwill generally increase as hardness is increased. In a two-piece solidgolf ball, e.g., a core and a cover, one of the purposes of the cover isto produce a gain in COR over that of the core. When the contribution ofthe core to high COR is substantial, a lesser contribution is requiredfrom the cover. Similarly, when the cover contributes substantially tohigh COR of the ball, a lesser contribution is needed from the core.

The present invention contemplates golf balls having CORs from about0.700 to about 0.850 at an inbound velocity of about 125 ft/sec. In oneembodiment, the COR is about 0.750 or greater, preferably about 0.780 orgreater. In another embodiment, the ball has a COR of greater than about0.790. In yet another embodiment, the COR of balls made according to theinvention is about 0.800 to about 0.815.

In addition, the inner ball preferably has a COR of about 0.780 or more.In one embodiment, the COR is about 0.790 or greater. Furthermore, asolid sphere formed from the composition of the invention has a COR ofabout 0.65 or greater. In one embodiment, the COR is about 0.75 orgreater. In another embodiment, the COR of the inner ball is about 0.76or greater. In still another embodiment, the COR of the inner ball isabout 0.77 or greater. In yet another embodiment, the COR of the innerball is about 0.79 or greater. For example, the inner ball may have aCOR of about 0.800 or greater.

Spin Rate

As known to those of ordinary skill in the art, the spin rate of a golfball will vary depending on the golf ball construction. In a multilayerball, e.g., a core, an intermediate layer, and a cover, wherein thecover is formed from the polyurea or polyurethane compositions of theinvention, the spin rate of the ball off a driver (“driver spin rate”)is substantially higher than balls having covers formed of conventionalpolyurethane or polyurea compositions. In one embodiment, the driverspin rate is about 3500 rpm or greater. In one embodiment, the driverspin rate is about 4000 rpm or greater. In another embodiment, thedriver spin rate is about 5000 rpm or greater. In still anotherembodiment, the driver spin rate is about 5200 rpm or greater.

In this regard, the spin rate of a golf ball constructed according tothe invention off of an 8-iron (“8-iron spin rate”) and a half wedge(“half-wedge spin rate”) is higher than the spin rate of a golf ballconstructed with the same inner components but with a cover formed froma conventional polyurethane or polyurea. For example, in one embodiment,the 8-iron spin rate is about 9000 rpm or greater, preferably about 9500rpm or greater. In one embodiment, the 8-iron spin rate is about 10000rpm or greater, preferably about 10500 rpm or greater. For example, the8-iron spin rate may be from about 11000 rpm to about 13000 rpm.Likewise, the half-wedge spin rate is about 7000 rpm or greater,preferably about 7500 rpm or greater, and more preferably about 8000 rpmor greater.

Two-piece balls made according to the invention may also have driverspin rates of 1500 rpm and greater. In one embodiment, the driver spinrate is about 2000 rpm to about 3300 rpm. Wound balls made according tothe invention preferably have similar spin rates.

Methods of determining the spin rate should be well understood by thoseof ordinary skill in the art. Examples of methods for determining thespin rate are disclosed in U.S. Pat. Nos. 6,500,073, 6,488,591,6,286,364, and 6,241,622, which are incorporated by reference herein intheir entirety.

Flexural Modulus

Accordingly, it is preferable that the golf balls of the presentinvention have an intermediate layer with a flexural modulus of about500 psi to about 500,000 psi, measured according to ASTM D-6272-98. Morepreferably, the flexural modulus of the intermediate layer is about1,000 psi to about 250,000 psi. Most preferably, the flexural modulus ofthe intermediate layer is about 2,000 psi to about 200,000 psi. In thisaspect of the invention, when the intermediate layer is formed of anionomeric material, the flexural modulus may be greater than about10,000 psi.

The flexural modulus of the cover layer is preferably about 40,000 psior less, and more preferably about 30,000 psi or less. In oneembodiment, the flexural modulus of the cover is from about 500 psi toabout 35,000 psi. More preferably, the flexural modulus of the coverlayer is about 500 psi to about 30,000 psi.

In one embodiment, the compositions of the invention are used in a golfball with multiple cover layers having essentially the same hardness,but differences in flexural moduli. In this aspect of the invention, thedifference between the flexural moduli of the two cover layers ispreferably about 5,000 psi or less. In another embodiment, thedifference in flexural moduli is about 500 psi or greater. In yetanother embodiment, the difference in the flexural moduli between thetwo cover layers, wherein at least one is reinforced is about 500 psi toabout 10,000 psi, preferably from about 500 psi to about 5,000 psi. Inone embodiment, the difference in flexural moduli between the two coverlayers formed of unreinforced or unmodified materials is about 1,000 psito about 2,500 psi.

Specific Gravity

The specific gravity of a cover or intermediate layer is preferably atleast about 0.7. In one embodiment, the specific gravity of theintermediate layer or cover is about 0.8 or greater, preferably about0.9 or greater. For example, in one embodiment, the golf ball has anintermediate layer with a specific gravity of about 0.9 or greater and acover having a specific gravity of about 0.95 or greater. In anotherembodiment, the intermediate layer or cover has a specific gravity ofabout 1.00 or greater. In yet another embodiment, the specific gravityof the intermediate layer or cover is about 1.05 or greater, preferablyabout 1.10 or greater.

The core may have a specific gravity of about 1.00 or greater,preferably 1.05 or greater. For example, a golf ball of the inventionmay have a core with a specific gravity of about 1.10 or greater and acover with a specific gravity of about 0.95 or greater.

Shear/Cut Resistance

The cut resistance of a golf ball cover may be determined using a sheartest having a scale from 1 to 9 assessing damage and appearance. In oneembodiment, the damage rank is preferably about 3 or less, morepreferably about 2 or less. In another embodiment, the damage rank isabout 1 or less. The appearance rank of a golf ball of the invention ispreferably about 3 or less. In one embodiment, the appearance rank isabout 2 or less, preferably about 1 or less.

EXAMPLES

The following non-limiting examples are merely illustrative of thepreferred embodiments of the present invention, and are not to beconstrued as limiting the invention, the scope of which is defined bythe appended claims. Parts are by weight unless otherwise indicated.

Example 1 Compositions of the Invention

Compositions formed according to the invention are outlined in Table 1below.

TABLE 1 COMPOSITION OF THE INVENTION Invention Experimental ControlPrepolymer Isocyanate- Reaction product of MDI Desmodur ® N-3400⁴Reaction product of MDI Containing and PTMEG 2000¹ and PTMEG 2000¹Component Isocyanate- Aminoalcohol⁵ Reactive Component Free NCO 6.0 6.56.0 Curing Agent Curing Agent Poly THF ® 650² Desmophen ® NH 1220⁶Ethacure 300⁷ Additive(s) 3.5% HCC-19584³ Ratio of 1:0.95 1:0.95 1:0.95Prepolymer to Curing Agent Material 12   14   48   Hardness (Shore D)¹Reaction product of diphenylmethane diisocyanate and polytetramethyleneether glycol with a molecular weight of 2000. ²Poly THF ® 650 is apolyether diol having a molecular weight of 650 from BASF Corporation.³HCC-19584 is a white dispersion manufactured by PolyOne. ⁴Desmodur ®N-3400 is a solvent free low viscosity aliphatic polyisocyanate resinbased on hexamethylene diisocyanate from Bayer. ⁵An aminoalcohol ofJeffamine ® D-2000, available from Huntsman, and a caprolactone monomer.⁶Desmophen ® NH 1220 is a solvent free amine-functional aspartic esterfrom Bayer. ⁷Ethacure ® 300 is an aromatic diamine (dimethylthiotoluenediamine (DMTDA)) from Albemarle Corporation.

Example 2 Balls Made According to an Embodiment of the Invention

The formulations in Example 1 were used to form covers on an inner ballthat includes a polybutadiene core and an ionomer resin casing layer. Inparticular, ball #1 was made with a cover formed according to theinvention, ball #2 was made with a cover formed according to theformulation designated in Example 1 as “experimental,” and ball #3 wasbased on Titlelist's Pro V1. All inner components of balls #1, #2, and#3 were identical. The physical characteristics of these balls are shownbelow in Table 2.

TABLE 2 PHYSICAL CHARACTERISTICS #1 #2 #3 Ball (Invention)(Experimental) (Pro V1) Cover Hardness 49/74 50/77 59/83 (Shore D/ShoreC) Compression (Atti) 87 85 87 COR at 125 ft/s 0.810 0.795 0.807 ImpactDurability @ 1 @370,375X 2 @ 388X No Failures 400 hits Cold Crack NoFailures Resistance at 5° F. Molded Ball Shear 1 2 1 RatingThe cover hardness for the ball #1 is comparable to ball #2 and lowerthan ball #3. As shown above, a ball with a cover made according to thepresent invention has comparable compression to a ball made with aconventional polyurethane, e.g., Pro V1, and slightly higher compressionthan a ball made with a polyurethane formulation having comparablehardness to the composition of the invention. Surprisingly, ball #1suffered no loss in COR over that of the control ball #3 and actuallygained COR over ball #2. In addition, the impact durability and moldedball shear rating of ball #1 is much improved over that of ball #2. Insum, when the formulation of the invention is used as a cover in athree-piece ball, a significant decrease in hardness is achieved withouta loss in COR.

As further shown below in Table 3, the driver spin rate, 8-iron spinrate, and half-wedge spin rate of a ball with a cover made according tothe present invention are substantially higher than the control ball #3.

TABLE 3 SPIN RATES #1 #3 Ball (Invention) (Pro V1) Std Driver Launch 7.69.2 Spin 5237 3129 Speed 161.7 161.1 8-Iron Launch 17.2 19.4 Spin 110798195 Speed 115.8 114.9 Half-Wedge Launch 29.7 31.0 Spin 8136 6957 Speed54.0 53.4As explained above, the inner ball construction of #1 and #3 areidentical. As such, without being bound to any particular theory, theincrease in spin is a result of the low material hardness of thecomposition used form the cover of ball #1.

Example 3 Three-Piece Ball Construction According to the Invention

Three-piece balls were constructed according to the invention includingcomponents having formulations and characteristics as set forth in Table4. The core formulation is based on 100 parts of rubber. The ball has acompression that ranges from 80 to 115 Atti and a coefficient ofrestitution that ranges from 0.800 to 0.820.

TABLE 4 THREE-PIECE BALL CONSTRUCTION ACCORDING TO THE INVENTION #4 #5CORE Formulation Shell 1220 100 100 Color Masterbatch 0.8 0.4 PerkadoxBC 1.16 — Trigonox 265 — 0.55 Regrind 16.0 16.0 Zinc Diacrylate (ZDA)32.1 32 Polywate 11.7 11.7 Zinc Oxide 4.86 4.86 ZincPentachlorothiophenol 2.35 — (ZnPCTP) Properties Outer Diameter (inches)1.520-1.580 Compression (Atti) 60-90 COR @ 125 ft/s >0.790 MooneyViscosity >30 INTERMEDIATE LAYER Formulation Surlyn ® 8940 50 Surlyn ®7940 50 Properties Flexural Modulus (psi) >10,000 Hardness (Shore D) >60Thickness (inches) 0.010-0.060 COVER Properties Material Hardness (Shore10-60 D) Flexural Modulus (psi)   500-30,000 Thickness (inches)0.010-0.080

Example 4 Four-Piece Ball According to the Invention

Four-piece balls were constructed according to the invention includingcenters and outer core layers having formulations and characteristics asset forth in Tables 5 and 6. The center and outer core layerformulations are based on 100 parts of rubber. Either of core A or B canbe used with either of outer core layer C or D in combination with theinner and outer cover layers set forth in Table 7. The specific gravityof the core and outer core layer material is essentially equal. The ballhas a compression that ranges from 97 to 105 Atti and a coefficient ofrestitution that ranges from 0.808 to 0.814.

TABLE 5 CENTER COMPONENT OF FOUR-PIECE BALL A B Formulation CB23 64.464.4 Shell 1220 35.6 35.6 Color Masterbatch 1.5 0.19 Perkadox BC 1.0 1.0Regrind 14.7 14.7 Zinc Diacrylate (ZDA) 22.2 22.2 Polywate 16.7 16.7Zinc Oxide 5.0 5.0 Zinc Pentachlorothiophenol 0.52 — (ZnPCTP) PropertiesDiameter (inches) 1.0-1.5 Compression (SCDI) >70 Mooney Viscosity >30

TABLE 6 OUTER CORE COMPONENT OF FOUR-PIECE BALL C D Formulation CB2391.0 91.0 Kurary 9.0 9.0 Color Masterbatch 0.53 0.26 Perkadox BC 1.0 —Trigonox — 0.5 Regrind 17.2 17.2 Zinc Diacrylate (ZDA) 40 40 Zinc Oxide13.0 13.0 Zinc Pentachlorothiophenol 2.35 — (ZnPCTP) Properties OuterDiameter (inches) 1.53-1.62 Compression (SCDI) >70 COR @ 125 ft/s >0.800Mooney Viscosity >30

TABLE 7 COVER LAYERS FOR FOUR-PIECE BALL INNER COVER LAYER FormulationSurlyn ® 8940 50 Surlyn ® 7940 50 Properties Flexural Modulus(psi) >10,000 Hardness (Shore D) >60 Thickness (inches) 0.010-0.060OUTER COVER LAYER Properties Material Hardness (Shore 10-60 D) FlexuralModulus (psi)   500-30,000 Thickness (inches) 0.010-0.080

As used herein, the term “about” is used in connection with one or morenumbers or numerical ranges, should be understood to refer to all suchnumbers, including all numbers in a range. Other than in the operatingexamples, or unless otherwise expressly specified, all of the numericalranges, amounts, values and percentages such as those for amounts ofmaterials, times and temperatures of reaction, ratios of amounts, valuesfor molecular weight (whether number average molecular weight (“M_(n)”)or weight average molecular weight (“M_(w)”), and others in thefollowing portion of the specification may be read as if prefaced by theword “about” even though the term “about” may not expressly appear withthe value, amount or range. Accordingly, unless indicated to thecontrary, the numerical parameters set forth in the followingspecification and attached claims are approximations that may varydepending upon the desired properties sought to be obtained by thepresent disclosure.

Notwithstanding that the numerical ranges and parameters setting forththe broad scope of the disclosure are approximations, the numericalvalues set forth in the specific examples are reported as precisely aspossible. Any numerical value, however, inherently contain certainerrors necessarily resulting from the standard deviation found in theirrespective testing measurements. Furthermore, when numerical ranges ofvarying scope are set forth herein, it is contemplated that anycombination of these values inclusive of the recited values may be used.

The invention described and claimed herein is not to be limited in scopeby the specific embodiments herein disclosed, since these embodimentsare intended as illustrations of several aspects of the invention. Anyequivalent embodiments are intended to be within the scope of thisinvention. For example, the compositions of the invention may also beused in golf equipment such as putter inserts, golf club heads andportions thereof, golf shoe portions, and golf bag portions. Indeed,various modifications of the invention in addition to those shown anddescribed herein will become apparent to those skilled in the art fromthe foregoing description. Such modifications are also intended to fallwithin the scope of the appended claims. All patents and patentapplications cited in the foregoing text are expressly incorporateherein by reference in their entirety.

What is claimed is:
 1. A golf ball comprising: a core; an inner coverlayer disposed about the core; and an outer cover layer disposed aboutthe inner cover layer, wherein the outer cover layer has a hardness ofabout 30 Shore D to about 60 Shore D and is formed from a castablematerial comprising: a prepolymer formed from the reaction product of atleast one isocyanate and polytetramethylene ether glycol, wherein theNCO content of the prepolymer ranges from about 5 percent to about 7percent; and a polyether diol having a molecular weight of about 400 toabout 2500 and having the following structure:

wherein n is the chain length from 2 to 30; wherein the castablematerial has a hardness of about 8 Shore D to about 16 Shore D.
 2. Thegolf ball of claim 1, wherein the composition comprises a ratio ofprepolymer to polyether diol of about 1:0.95.
 3. The golf ball of claim1, wherein the material hardness is about 10 Shore D to about 14 ShoreD.
 4. The golf ball of claim 1, wherein the golf ball has a COR of about0.810 or greater at 125 ft/s.
 5. The golf ball of claim 1, wherein theprepolymer has an NCO content of about 6 percent to about 6.5 percent.6. The golf ball of claim 1, wherein the difference between the flexuralmoduli of the inner cover layer and outer cover layer is about 5,000 psior less.
 7. The golf ball of claim 1, wherein the polyether diol has achain length n of about 7 to about
 27. 8. The golf ball of claim 1,wherein the polyether diol has a molecular weight of about 650 to about2000.
 9. A golf ball comprising: a core; and a cover having a hardnessof about 40 Shore D to about 55 Shore D, wherein the cover is formedfrom a castable material comprising: a prepolymer formed from thereaction product of at least one isocyanate-containing component and atleast one isocyanate-reactive component; and a polyether diol having amolecular weight of about 400 to about 2500 and having the followingstructure:

wherein n is the chain length from 2 to 30; wherein the castablematerial has a hardness of about 8 Shore D to about 16 Shore D.
 10. Thegolf ball of claim 9, wherein the golf ball has a COR of about 0.810 orgreater at 125 ft/s.
 11. The golf ball of claim 9, wherein theprepolymer comprises a reaction product of di phenyl methanediisocyanate and polytetramethylene ether glycol.
 12. The golf ball ofclaim 9, wherein the golf ball has an 8-iron spin rate of about 10,000rpm or greater.
 13. The golf ball of claim 9, wherein the castablematerial comprises a ratio of prepolymer to polyether diol of about1:0.95.
 14. The golf ball of claim 9, wherein the polyether diol has achain length n of about 7 to about
 27. 15. The golf ball of claim 9,wherein the castable material has a hardness of about 8 Shore D to about14 Shore D.
 16. A golf ball comprising: a core; a cover; and anintermediate layer disposed between the core and the cover, wherein thecover has a hardness of about 40 Shore D to about 55 Shore D and isformed from a castable material comprising: a prepolymer formed from atleast one aromatic diisocyanate and at least one polyol, wherein the NCOcontent of the prepolymer ranges from about 5 percent to about 7percent; and a polyether diol having the following structure:

wherein n is the chain length from 2 to 30; wherein the castablematerial has a hardness of about 8 Shore D to about 16 Shore D.
 17. Thegolf ball of claim 16, wherein the flexural modulus of the intermediatelayer is about 2,000 psi to about 200,000 psi.
 18. The golf ball ofclaim 16, wherein the golf ball has a driver spin rate of about 5,000rpm or greater.
 19. The golf ball of claim 16, wherein the polyetherdiol has a molecular weight of about 650 to about
 2000. 20. The golfball of claim 16, wherein the polyether diol has a chain length n ofabout 7 to about 27.